I'm no expert, but it will work well either way. If you want to do a flat belly, you will need the bl if you don't want a massive hole in the floor. So me personally I'd go the 3" spring with 1"bl.
Ironically that is what I have sitting waiting for me to be unlazy. Dropping from 6" lift to re 3.5" springs but no bl and 37's. just need some time to work on it and money for highlines.
05 Tj d44's, 4.88's, ARB's, 37's and some bling
03 terminator built - FOR SALE
14 RAM 1500
07 SRT 8 grand