Good Evening.

So, I've been swanning about the internet as you do and I've seen a few cool things. Mostly sentry systems or auto guns just less leathal. I've seen two so far;

http://members.upc.nl/a.kutsenko/guide.htm
http://www.paintballsentry.com/instructions.html

Now, I wouldn't mind having a go with either of these but the controllers cost £80+ which seems very expensive for something I just want to have a play with then probably dump or switch to something else. I've seen el-cheapo usb controllers on ebay for £30 as I have servos but I'm sure I'm missing something important.

I remember from the good ol' days of CPC that there where/was at least one robotic person. So any advice?

I think that Maplins sell a kit where you make your own controller. One of those project kit things where you solder components to a PCB. Much more fun than buying one ready made

And I don't think you're missing anything. As long as you have the servos and a way of controlling them, you're set.