Thanks guys. captain Jack, once I get it going with a reasonable facsimile I will post some pictures as such, but basically you will need to convert to servo rotation first (electronics wise it is easy, you just put a continuous servo on another channel of the receiver) and there is an easy way and a hard way to do the installation of the servo. The easy way is just replacing the HL rotation unit with a servo. The hard way which I did was to actually install the servo on the lower hull, similar to real tanks where the turret basically just sits on the rotation motor/servo. The reason I went this route is because once you detached the upper hull/turret from the lower, your turret is free to spin, unlike stock HLs.
Second piece is the gyro. I used GA-250 from HobbyKing because of a video posted by Kevin from RCTA on how to do turret locking with his Geko product and the GA-250. The most difficult part on the GA-250 is the configuration, but once I figure out how to get into configuration mode it was easy peasy.
MikeC.