I've got a 1955, 1966, 1968 Beetle and 1974 Thing and we fix a lot of air-cooled VWs and Porsches at Eclectic Motorworks. A lot of the comments above are valid, and I'll add a few.
I daily drive my bone-stock 1966. It still has 6V electrics, drum brakes, and the stock 1300 single port engine. It goes just above 70 MPH, so it's not a great freeway car, but in town I love it. Easy to park, easy on gas, great visibility, great air flow on a hot day (I have a light blue exterior with an off-white interior--much cooler than black), very reliable. I used to daily drive my 1968 and it had a 1600 dual port at the time. It had a little more torque but really no more top speed. The interweb always says go for 1600 dual port and will too, if you're replacing your engine, but I can say with experience that you can do okay with a smaller engine.
I'll take a polite exception to the disk brake conversion as a necessity. If the factory brakes are properly done, they'll lock up all four wheels consistently for a lot of stops with little or no fade. We see a lot of cars with really poorly "rebuilt" braking systems, often with customers that want disk conversions. We almost always convince them to have us redo their stock brakes after they've driven my 1966 Beetle. We've worked with several versions, and many are of sub-standard quality. We've seen caliper brackets flex, poorly sized piston matches, iffy components, and other issues with some conversions. If you really want front disks, the Ghia setup is the best choice. And it's much easier to keep a good disk setup performing well--no adjustment, few parts, etc. Key point is that you don't need disks, but if you want them, get a proven setup as there are a lot of bad ones.
I think the key in purchasing is finding a car that has been well-maintained and is well-sorted. A lot of cars on the market are pigs to drive because they have all the right parts, but not the right adjustments. I've already mentioned brakes, but there will be tuning issues and power losses because fewer mechanics understand points and carbs, there will be alignment issues, there will be electrical issues, etc.. A good car will drive straight, stop with confidence (and straightness), feel tight, feel light and easy to handle, accelerate to 30 MPH smoothly and reasonably fast (accelerating to 60 MPH is another story), and make you smile. About 3/4s of the cars you drive won't do that due to sorting issues. So look at and drive several before you decide to buy.
I can pick from some pretty cool cars to daily drive--E-Type, Mini, Lotus, Porsche, Alfa, etc. and I keep going back to my Beetle. California is a great place to find one. Good luck.