Mactruc, since it sounds like you're on a serious budget I'd suggest just do the inexpensive elbow grease mods to your pair of old Spyders and go play. In the woodsball arena there's still very much a place for old mechanicals. And if you get into a fix where you needed a higher fire rate to get out of it then you shouldn't have gotten yourself into that spot in the first place...
You'll likely need to spend some cash on new hammer Orings. Those are the ones that are like gummybears in consistency and when they get old and harder they just don't let the gun blowback and recock as easily. If they are still good count yourself lucky.