you wont get that fat tone but my RotoSound FunkMaster strings work great for slap and pop. their gauge is .030-.090 but they still have a nice bottom end
Long long ago I loved Blue Steels for slapping, truly awesome, but when I moved to 5 string they couldn't help me (because for a good few years they only did 4 string sets; I think I've seen a 5 string set more recently but not bothered with them).
If you haven't tried Warwick Black Label strings and like an "everything's here" slap tone, give them a try first. I've also had great results with Ken Smith stainless steel strings.