You should be clear on what you want, seat time or a ranger that is capable of track work. It's not realistic that you'll have both in any kind of short time frame. If you spend lots of time building a ranger only to take it to the track and realize you don't enjoy it that would suck. If you get an EZ button trackday car now that you can use while you build your ranger, you will probably decide to either ditch the ranger because seat time is fun, or ditch the trackday car because you like building better than driving.
I have an 03 reg cab short bed 2wd 2.3 M50D and it's great fun on the street. It will rotate on trailing throttle, it's predictable, tossable, moves around alot, never settled, and very very SLOW. The slow part is what makes it fun, the limits are so low that you can actually have fun without being a menace. And it is a real truck, so it hauls mulch, 4x8 sheets/drywall, engines, bicycles, motorcycles, whatever.
But I would not use it at a trackday, the brakes are nowhere near adequate for the track, the steering is super slow, the balance at higher speeds is too pushy, it needs real seats, and I suspect overall that many things would start to fail if you carry any kind of fast track pace. All of these are fixable of course, just as anything can be fast and reliable with enough time and money thrown at it, but for me that level of investment isn't worth it.
For reference my spec is very simple, any more and my feel is that it gets out of hand:
Front - 3" bell tech springs, PRO hobby stock 2nd gen camaro dampers, I have the bell 1-1/4" stabar but I think it would push to much with it and haven't tried it.
Rear - 8.8 explorer disk brake positrac (flipped), stock leafs with new bushings/shackles, AFCO shocks outside the frame rails, howe aluminum driveshaft to fit the 8.8
Also if you use it as a real truck things get ugly over time, my rear shock mounts looked like this new (before paint), but now after a few midwest winters they look so old and cruddy that they could be OEM. Feels bad man.