About how much would it cost me to upgrade a savage for reverse and a bigger engine that would match the tmaxx in speed?

Well, I can tell you the reverse module is $45, then you need a servo to drive it. The savage comes with 3 channels stock, so your radio gear will be fine.

yeah the reverse is 45$ and all you need is standard servo so it's not to much for that as for the engine it depends on what you want.The Ofna Hyper21 8 port and the Force .25 are good swaps and cost about the same (140$-150$) depending on where you look.I think XTM makes a .25 that fits too but not sure how much it costs.