btl loves power. if its 1500wrms from a solid amp it will be good. besides you can always upgrade. heck, you can even get another 1500 wrms amp and put both on that sub later.
^ But if the amps aren't linkable you could end up putting 2 amps on 1 sub and getting the same power
If you plan on upgrading your electrical system enough to take 2500rms+ watts for the btl, and upgrade your amp, you'll be good. If you don't plan on upgrading electrical and amps down the road, I'd save the money and get a BL.