I have an ampeg v4bh classic tube amp head and am looking to get a kustom 2x15 head and am wondering if they will sound good together for an indie rock band?
Assuming you mean cab, not head. I wouldn't bother with 15's though, there's no need for them if you're using modern equipment (this will probably cause some controversy :P).
No, it won't be problematic. It should work fine. Most bassists have gravitated toward 10" speakers in the last few decades, but if you like 15" speakers, then go for it. You should be able to shake a few rafters with that setup.
(this will probably cause some controversy :P).
It's okay, you know how absurdly wrong you are.