Counterweights

Does anybody have a sliding counterweight system they use to balance out heavy eyepieces (or cameras)? The only thing I really see for sale is the Meade system, but it is only supposed to be for the LX200's. I like the concept, but before I buy a set and jimmy it around for my celestron 120 I want to see if there are other (or better) options.

Losmandy makes sliding counterweights. Look at their V-series components, you might be able to use those parts.