I expect Steve to respond here soon enough! I would definitely go for one of the boards he has. I believe he used a Korg Trinity in the past? I could be mistaken, but either way, Trinities are pretty cool, and shouldn't be too expensive these days, especially if you get one used.
According to the website, Steve currently uses a Korg Triton Extreme (awesome board!), Korg Triton Pro, and a Nord Lead 3, as well as the famed Roland AX-7 keytar.
I highly recommend all of those. Korg is the way to go if you want awesome synths, in my opinion! However, those are all pretty high-end pieces of equipment, so maybe you'd be better off getting a low level Yamaha. Kurzweil is amazing if you want piano, but I don't recommend Casio for anything at all unless you really don't care about the sound and just want something to play on. Just my opinion, as I'm a keyboardist as well.