Prog Rock is def. one of my favorite genres. You can have so much fun with it!
My main musiacl influence is Dream Theater and I often find my playing and songwriting style similar to their's. You shoud listen to all different bands and see how they arrange songs. Having a keyboard player would be a great asset to the band! The only prob. is you need some good money to get some really great sounds out of one. You should ask around for keyboard players and have tryouts. There is always someone close by with amazing talent. You just have to look a little bit.