I've heard too about the traditionalists who'll only listen to BG played on an acoustic double bass, but then I've looked on Talkbass and seen guys playing an NS Design EUB at country music awards and stuff, so it can't be that bad, maybe that was Nu-Grass?. If you really want to get into upright then an acoustic DB is the way to go, but if you haven't played one before you'd need to invest in some time to adapt your technique. As to instruments, as long as you get a usable sound I'd play whatever instrument you like, and if other people don't like it that's their problem. Get some flat wound strings such as La Bella Deep Talkin Bass strings & avoid rounds 😉