I'd suggest using a 12 for a single sub setup. Or custom build a ported box for a 10.
I don't know how much bass you are actually looking for. For me 2 10s is the smallest I'd go. 1 12 is ok I just want more personally. This is all sealed boxes of course.
If you get a custom design for a ported box you can get alot more out of the same subs. You will just use typically twice the space for ported then sealed.
@Shredder can help you with a design if you want to go that route
Cost to build yourself is minimal if you have the tools to do it. $60-$80