I know a guy who could make you the hardware exactly how you would like it. He's an old friend and he makes effects units and custom instruments. I have no idea how much he would charge you however.
If it's an organic sound your after you could try something a little radical like this:
http://www.zzounds.com/item--ALEAIRFXOr for a cheaper more normal effects unit how about one of these:
http://www.alesis.com/nanoverb2only £80 on ebay and well respected.