Thanks for the replies, this helps.
The only reason I was looking at the ipac ultimate was that rgb element built in, and that you can load custom configs for controller when game launches, for either keyboard or xinput.
I don't mind using an alternative, but I keep running into limited outputs for 2-player, eight button each, plus Start, Menu, Coin, Pause, Exit. Meaning I would have to buy multiples of whatever I'm looking at, unless someone has a decent input encoder and also lighting controller in mind.
I've thought about non rgb, which I would prefer, but I think for ease of use, it would be good for the kids, if the buttons lit up according to the game. Plus for games that give instructions (like most newer fighting games), color coding would be beneficial.