Have you considered small deccabons instead? When hit with sticks, bongos sound pretty much just like these:
https://www.amazon.com/dp/B015SW6OX6?psc=1
Toca has a nice set of bongos with fiberskin heads. I've never tried playing them with sticks, though.
Roto toms are a totally different sound than deccabons. Lots more attack, less body. The shell really makes a difference.
If you're totally stuck on bongos though, Remo makes a million different plastic headed models. Here's some examples:
https://www.amazon.com/dp/B0002Q1XL2/ref=twister_B00IST8RXC?_encoding=UTF8&psc=1
https://www.amazon.com/CR-P780-00-n...F8&qid=1485728507&sr=1-4&keywords=remo+bongos