I'd like eventually mount a scope on my 870 and I'd like to hear some opinions as to which mount would be better. Buying a new barrel with a cantelever mount or having a gunsmith to drill and tap the receiver would cost too much. I've seen saddle mounts for about $25 but I read the mount coming back and catching the shooting finger. I've also seen cantelever mounts that attach to the vent rib, has anyone ever tried these?

I have all the setups you are asking. The best bar non is the cantilever. If that is not an option then go with the drill and mount (base) it maybe a few bucks more but the height of the scope will be right and you won't have to rise off the stock to take a shot....

getting the receiver drilled and tapped is fairly cheap...much cheaper than a new cantilever barrel. Unless you already have the cantilever or you don't want to have the scope permanently mounted i would get it drilled and tapped. I just had my 870 done a few years ago at Gander...can't remember what it cost me, I want to say about 50 bucks.