I am debating on whether to get a snail shell and then only 1 sub, or if I should save the money and buy 2 subs and build my own box. I'm not sure which would be louder/hit harder, but if I was going to build my own box is there any place I could get some specs so I could make a decent box instead of a regular ported box.
Depends on what you want. What do you meen by "regular ported box" I'm not sure what else you think your gonna build besides ported or sealed. You could try different kinds of bandpass enclosures, but their very hard to make. As for specs, your gonna have to decide on a sub first.