Okay, what back-end would be suitable for multiple pools similar to slush's pool but on a smaller scale and how many could you work onto a single server? I hope that makes more sense.
Im unsure if this is the place to post about it but ill try offer a few tips;
There are a few back ends you can use;
stratum-mining (Python)
NOMP (Node.JS)
CoiniumServ (Mono)
Im still unsure if you are talking about pools for altcoins or what? Im assuming you are as you would only need a single pool just for Bitcoin.
There are a few guides and tips around the forum, please be ware running a pool isn't easy work, and make sure you have background knowledge of how things work etc otherwise if something goes wrong you won't know how to fix it.