As mentioned in several posts above, the chances of making your Tele sound like an SG are very very small. However, you might end up with something "different" - not a Tele, not an SG, not a Les Paul, but something with a strong personality of its own.
This one is equipped with a GFS Dream90 at the neck and a GFS Classic II at the bridge (on the pic it's a Duncan Antiquity but after three gigs with the Ant I went back to the GFS I originally put in it

).
The Classic II is a very low output humbucker, and if I absolutely have to compare this guitar with a model from the Gibson family, I guess the closest would be a Firebird. But most importantly it's a totally unique guitar with a strong identity, and it's become my favorite. It has the Tele "snap", lots of clarity, yet warmer and fuller sounding than my 'plain' Tele.