Funk is in the fingers....but imo....Fender Jazz type basses and MM Sterlings and Rays get the job done real good....and the right P bass can get real classic funk tones. Of course there are plenty of other options...but these are what most of the funk players in my city go to work with.
For real though... take some of those classic funk lines from someone like Bootsy and try to play them as a beginner on upright. That's where I am right now. Wow.
A Jazz bass or a Stingray both work great for Funk. But I gotta go with Bootsy's bass as the absolute winner.
Oh gee whiz...I misread the title as "best brand for slap," not "funk." Eh, what the hey...I'll go upright there, too
Ha ha! Darn kids...this link is it...and i fixed the one above....too funny.. Some funky Upright bass
Any bass with strings. Funk is what you play and, especially, what you don't play. Everything else is fluff.