If you go with the TC4 for VTA, you'll need to keep some things in mind.
1. To get down to a recommended 4.0 FDR for the 25.5 you'll need to get some of the smallest spurs they make in 64 pitch.
2. This will also require some fairly large pinions.
3. All of this requires some Dremel work on the chassis and motor mount to accomodate the spur/pinion combo.
4. All that said, I have a TC3 for VTA with an 88/53 (or 55) and love the car. Easy to work on, handles great, tough as nails.