You've had a lot of good feedback from everybody on multiple threads. The major responses have been: 1) get some training and 2) put real tires/wheels on it (ideally 18" with good sidewalls, and probably LT (light truck) E-rated, high load index, 10 ply).
You could probably get away with putting some sort of 19" tires on there but you'll run into all the issues you've already heard - not enough tire selection, most of them are SUV/passenger rated, most of them will not survive long in real off-road conditions because of their weak sidewalls and you'll likely end up having to buy $1000 worth of tires now and then another $3K worth of "real wheels and tires" later.
Personally I like to "buy once, cry once" vs. keep buying replacements. I've tried going the cheap tire route and it cost me multiple tires, delays in my trips, and extra repair expenses. I won't make that mistake again.
I find it interesting that your initial starting list was probably $10K-15K worth of modifications (front and rear bumper, sliders, wheels / tires, and other stuff), yet you're balking at spending the first $3K on the most important thing of all. This is really the critical first step.
If you really didn't want to spend any money, then throw 19" tires on, be careful, hope for the best and get out there and don't spend any more money on it until you feel like you're really committed to this vehicle. That's my 2 (12?) cents.
