I need to update the speakers in the truck

I've never been good at speaker crap, but I do like good tunes.  What should I get in 6.5" and 6"x8"?

Head unit is a JVC KD-X260BT, I can upgrade that as well but I got a good deal on that and it isn't that old.

I'm hardly an expert, but I used to build hi-fi home audio speakers.  Focal always made really good drivers for home applications.  When I wanted to upgrade the speakers in my truck, I listened to Focal's coaxial 6.5" speakers compared to a bunch of the other big names.  I was kinda amazed how much better the Focals sounded, it was like night and day.  So that's my n=1.

If you plan to drive them with the head unit, definitely check on the speaker's efficiency.  Low efficiency speakers sound like garbage without a proper amp.

Ive tried most. The best ive come across consistently is infinity reference speakers. As a matter of fact,  i have those or Memphis speakers in almost every car i own. 

I would spend the money on infinity reference every time. 

i love my focal   but i spent big money.

you don't mentions a price , but morel maximo utltra  a considered great bang for buck   around 150 a pair

another brand to look at is the hertz.  none of these are "mainstream brands"  but 

Quick primer.

Range.  Wider is better.  All will be able to reproduce sound up to about 20khz, so don't focus on the high frequencies.  Focus on the low frequencies they can produce.  The range of sound they can produce will be listed as something like 60hz-20khz.  Those numbers are the 3db point.  That is to say, as they reach the upper and lower limits of what they can produce, volume (in decibels) drops.  Once the volume drops 3db, that's where they rate the end of the range.

Efficiency/sensitivity.  more is better.  It's measured by db/watt.  They set up a microphone 1 meter away and give the speaker 1 watt of a tone.  The db it's able to create is it's efficiency.  This measures how effectively the speakers can turn the electricity into sound.  This also ties hand in hand to....

Power handling.  More is not better because it usually means they have huge magnets and coils to handle the power, which lowers it's efficiency.  Putting top-of-the-line speakers on just little wattage from a head unit will be a mismatch.  Speakers are also rated kinda like generators.  They have a constant power they can handle and a brief peak power they can take intermittently.  The rated power is the real number you should focus on, listed as RMS.  You might see 50wrms.  That's your number.  Not peak.  This is true of both speakers and the amplifier/head unit you're using.

Head unit power.  More is better, but don't listen to what they tell you.  It might say 40w hi-power, but it isn't.  It's probably more like 12w.  They are limited by how much power they can handle given the small space in the head unit.  Think of it like a Miata engine trying to drive a dually truck.

As a big generalization, as you go up in price within a speaker brand, they are going up in power handling and down in efficiency which is exactly what you don't need.  You can find speakers that have been engineered for high power AND have high efficiency, but they are usually super expensive.

Coax vs. Separates.  Coax speakers are the normal ones you see; a woofer cone with a tweeter in the middle.  Component speakers are the ones with a separate tweeter you can mount somewhere else.  Coax is tried and true.  Component typically adds cost and is nice for an audiophile who really wants to tune the soundstage.  Stick with Coax.  screw it in, hook it up, done.

You need a speaker that focuses on quality materials, high sensitivity, and modest power handling.  That will take your relatively small power from the head unit and use it wisely.  The quality materials will allow for higher volumes without the speaker distorting, maxing out its excursion, or generally sounding like crap.  Don't shy away from paper cones.  They are rigid and can actually help bass production, they just aren't as durable.  Poly cones work well at lasting forever, but they can wobble and not be as accurate.

TL;DR.  Polk dB, Fosgate Punch, CDT's CL line, MBQuart's PVM line.  All will do well.  They offer top notch materials, not overly expensive, and great sensitivity.

I have CDTs in the van, Fosgate Punch in the BRanger, and Polk dB on the motorcycle.

Oh.... woofersetc.com.  You'll thank me.  Steep discounts on closeouts, good discounts on current stuff, and lots of options for super cheap refurb stuff.

Then check out the same stuff on Crutchfield.  It might be $2 more, but the customer service is AMAZING.

I said it before and I'll say it again—Pioneer 2 or 3 ways. The 6.5s will be $25-ish from Amazon, the 6x8s $35 from eBay. For the money, nothing comes close until you spend a ton more and go with external amplification. I've had both of these size Pioneer speakers in many of my cars, and the change is so delightful and consistent it's to the point now that when I pick up an older vehicle, I usually order them at the same time I put in my initial RockAuto consumables order.

I recently branched off when picking out audio for a car I flipped the other month, just to try something new, and see if anything cheaper was better. Tried JVC 2-way 6.5s and Pyle 3-way 6.5s. The JVCs had a great sensitivity but were absolutely flat—the Pyles sounded better but not great.