The shagler - there are two ways of looking at this.
1. If you want a good reliable on road car - Go with the NTC3. It is the only car on the market, that can be used as a daily driver, yet still consistantly win races without any hop-ups. Parts for it are everywhere, and it handles like a dream. Will also stay together very well, and hit spees of about 55mph. This vehicle uses either a .15 or a .12 small block.
2. If you want top speed, and that is it, you can go two different ways. Fist, you mentioned that you wanted something that used the same mill as your savage, which is a .21 big-block. Unless you feel like forking over 1000,s of dollars to get a 1/8th scale, the Schumaker Fusion is really your only choice. The good news is that it is the fastest TC out there. it will hit speeds of over 80mph as claimed by the manufacturer. The downside, is that the car is imported from overseas and has very little support over here. This will cause problems, as you wait 2 weeks, for that 1 part you broke. The other choice is the new Traxxas 2.5 4-tec. This car is supposed to exceed 60mph, and has more support than the schumaker. Good luck!
BTW - I would recommend the NTC3 - you will be happier in the long run.