For blues = P bass is my understanding. But if the idea is to do a bit more diddly diddly up the dusty end than is usual in blues, quick shake of jazz, plus maybe a dollop of funk, even (no, how awful) a hint of slap once in a long while, have you been down this road and come up with solid suggestions? P bass, J bass, 4, 5, 6 string, soapbar, splits or j bass pick ups?
Before anyone rightly says 'whatever, any bass will do, just play the b***** thing', I agree. But if the bass rack is almost empty and the wallet open, which way?