A few comments:
Because my 4.0 was losing oil pressure, I considered a V8 swap but ended up with a stroker for simplicity. In retrospect, its been good. I daily my Jeep and enjoy rocks. V8 swaps are cool but complicated and prone to overheating on the trail for some. Also, in the short wheel base TJ with stock axles, an LS or hemi is just too much power to use, IMO (plenty will disagree here). The stroker has 25% more power and torque than the 4.0 which doesn't knock your socks off but is nice bump. Lastly, I
really wouldn't rec a 4BT. I have a 4BT swapped into an old GMC chassis cab truck with an NV4500. I use it as a water truck during fire season and a back up for general truck stuff the rest of the year. It works very well for my needs. Its also the best demonstration of the diff between HP (very little) and torque (gobs) I've ever driven. For a TJ, the torque would be great, but you can get that with gearing and the HP would actually be less. The down sides are weight (700#) which will screw up performance both on and off road and its very, very loud and not just a little smoky.
Having said all of that, if fun to modify Jeeps so do whatever sounds good to you and re-do it if you don't like it