Most common asking price for a 939 series 20k front hydro winch on SS classifieds is about $1500 fairly complete, minus frame extensions. Those are another $500 or so as buy-it-now from a vendor unless you shop them around (time saves money thing). PTO can be put on trans without moving or removing trans, but it is extremely tight doing so. May need to cut wrenches down, put mounting studs in after PTO in place, that kind of stuff, but can and has been done numerous times. If a winch truck (925) is $2000 more, you can then get the winch with zero work or scrounging for parts (hydro filter, tank, brackets, etc...). That's how I did mine. Personally, I would not own one of these without a winch because I like to really play with it, not be scared to go wherever, and a smaller truck may not pull it out. I'm actually putting the same winch on the rear also just to have "fearless" mode. I had a mechanical artificial heart valve put in, I don't really trust it, and I bought my 925A2 as a survival present to self, so I am going to have fun with it even if end up destroying it (no intentions of such). Some stories and pics here require 2-3 equal sized trucks or a dozer to pull them out once stuck. If you will keep it out of mud and such, then you probably can skip the winch, unless you want the look. A 923 truck can be had for significant less cost, and it is otherwise the same cool a$$ truck.
A1 version gets terrible mileage (4mpg), A2 gets double (10mpg). These are approx. Consider that also if you plan to drive it a reasonable amount or if it is just a weekend warrior thing. A1 has decent low end torque, A2 has none until the turbo is awake. A1 sounds like a semi truck (same base engine), A2 sounds like a school bus (same engine, nearly exact). Fun trucks no matter what. Buying from an individual lowers your risk significantly as you can spend some time with it and test drive, etc...., and that is worth $ if you just want to sign and drive and minimize work required. I think you are asking good questions. Check prices on the classifieds here, and of a Craigslist in your surrounding areas if any are listed. There are search engines that check all CraigsLists of your entire state in one swoop. eBay completed auctions which sold is a common go-to for me to judge lowest achievable market value if you had to get out of it for whatever reason.
I bought mine from an SS member a couple of states away and kept money in the family. Good luck and welcome.