Well, I'm sure many will be responding to your post with their own opinions but I'll tell you what I use and it works very well for me. I use a Korg Triton with 88 wieghted keys and an X Y joystick controller. I think it's important to have 88 keys so as to not limit your keyswitching potential (VSL can be keyswitch intensive depending on your matrixes). Whether they're weighted keys or not I don't think matters all that much unless you write for and plan to use keyboarded instruments in your work. Like I said, I use a joystick controller and it works very well for me but many users swear on the breath controller. So you might want to get a keyboard that allows you to set up a breath controller. I had a real hard time trying to get my ribbon controller to work convincingly so you might want to stay away from that.
Just my thoughts.