so if you are thinking about rgb nodes, skip the dumb and do smart. then you are looking at pixel controllers.
go with a e1.31 controller so cheap Chinese controllers (t1xxx) are out. if you think a pixel mega tree is in your future, get a 16 port controller to keep it simple. almost all 16 port controller will come with a dmx bridge built-in, some will have several, some can do renard as well.