Should these be ok? Any issues so far with any of them?
I tested some compatibilities of plugins between RC 0.7 and 0.8 a while ago:
http://www.claudiokuenzler.com/blog/267/testing-roundcube-0.8-rc-larry-skin-plugin-compatibility
Most of them (at least the ones in development) work fine. For some you will have to get a special version for 0.8.