hello David,
 > dont i need a keyboard to play the A100 mini
Not necessarily. I guess that depends on your definition
 of "play". :)
 For traditional stuff yes though there are a multitude of alternate
 controllers: Theremin, ribbons, step sequencers, random voltage
 outputs etc. Some info:
http://www.doepfer.de/a178.htm
http://www.doepfer.de/a198.htm
http://www.doepfer.de/a155.htm
http://www.doepfer.de/a118.htm
 And of course things like foot control modules and the light
 controller:
http://www.doepfer.de/a177.htm
http://www.doepfer.de/a179.htm
 A lot of our customers actually do not use keyboards at all.
 And many others including myself are looking forward to the upcoming
 Touch keyboard/rack control surface w/sequencer to interface with
 the A-100:
http://www.doepfer.de/a100tkb.htm
 I would certainly consider starting with the Mini System. As Dieter
 mentioned you can buy it in a 6u frame for not much more than the 3u
 version and then add to it as either your budget grows or as you
 learn each module one by one.
 Also don't forget that you don't have to stick to the exact module
 configuation in the Mini System to get a system discount. You can
 swap a few modules out *within* reason.
 Feel free to email me with any comments or questions...
 Thanks,
 Shawn Cleary
 www.analoguehaven.com