I understand about being tapped out. I found that with a simple mod I could get Danos in the humbucker rout. I had to make pickup covers though, and that was a ton of work.
Another thing you might consider is to use something like a DiMarzio X2N or X2N7. They are not, strictly speaking, a bass pickup, but they've been uses in basses. The "7" is a bit wider for 7 string guitars and might work well with a bass if it will fit in the rout...
Lots of cheaper bar humbuckers that should work fine for bass as long as they are wide enough.