You are going to be pushing the limits of what the drive-train can handle with those bigger tires. Also did you check to see if that battery will fit? I don't think it will... It has a Traxxas connector too which won't work.... It will probably weigh more than the truck!:ror:
As far as the controller goes, they are a proprietary system. which means you will have to swap out all the electronics. I personally would just suck it up and get used to the pistol style remote. I think you will find it better in the long run. And no you will not find all this for around $50.
You are going to be way over your budget at this rate. I whole heartily agree with everyone above that you should have saved up a bit more and just bought hobby grade to begin with. I find that it is these very instances that frustrate a newcomer and deter them from the hobby.
FYI:
https://www.amazon.com/DKRC-Wltoys-...F8&qid=1498259249&sr=1-1&keywords=wltoys+k949
A little more money, but you are already getting there anyway AND all the Twin Hammers parts fit it! So worth it in the long run...
Good luck!