I got the entire turbine gasket kit, but the gasket that was bad cost under 20USD. Pretty easy to change, so I did it myself but I thought the GT2535 was a direct swap and excluding the lines and inlet it is. Now Im waiting on those parts since I figured I'd save tim by swappin now. If you DIY it should be less than 3 hours for a first timer. You gotta pull it apart anyway Id suggest going with the turbine gasket kit,. Worst it could be is a broken exhuast stud which I have replaced on a previous RB also.
Check all your flanges also, working backward to the turbine. Also if one of your gaskets are shot your gonna more of an exhuast sound from the engine or area affected.