As far as controlling the rack Viruses (Virii?), you would need to have a midi controller..
There are a number of good choices, depending on your budget..
In the low, low budget category (under $300), you could scout around for a cheap Fatar midi controller and grab a used
TG-33,
Kawai K4r, Oberheim Matrix,
Ensoniq VFX etc. off of Ebay. You could also grab a used
Yamaha An1x, which incorporates a keyboard and thick 10 voice analog synth.
In what I perceive as the next price level, you could get
an Alesis Ion, or one of the Waldorf synths (Micro Q, etc.), or one of the keyboard versions of the Novation polysynths. Better yet, keep an eye out for a used JP-8000.
If you choose to use softsynths, you can get a new harddrive, a good midi controller,a good VST-friendly sequencer, a bunch of FREE synths and some FREE effects off the web, and be in good shape for under $500.
I have a Virus A which I use frequently, but I find my self using a lot of older gear when my work (film scoring/commercial music) requires me to get a dense electro-industrial sound.
Regards,
Kit Dennis