if your willing to spend that much you should just go for the RPK, i'm in love with those. And from what i've seen there are not too many of em! its like 400$ for the kit tho. If not i also agree with madcat with the whole launcher thing. Otherwise.....yea if your going to strip everything from it you might as well as go with a cheaper AK, such as the Echo 1 or something. Why spend the money on a TM when your going to replace everything anyway.
As for Theyeti, yes you can change them i believe they should be the same version gearbox. all you need to do would be to buy a wood kit, and a longer inner barrel. Also i think some websites, such as wgcshop have some front end assemblies that you will also need. so it will cost you some bank.