I ended up spending around 600 dollars to do my MTB build/conversion, I don't know if i started off with a better platform though i used an 87' Kuwahara panther main reason for that particular bike is it's crazy long chain stays. But if you do the conversion like i did with the drop bars be ready for headaches, as components do not always match up with each other and part of my 600 dollars was from having to buy multiple parts over and over to find stuff that worked well with each other, of course if i went with bar end shifters from the get go i would have saved my self a bunch of money and time. So basically if you have knowledge of working on bikes and have the time to do it, MTB's make for great tourers(at least for me).
This is what mine turned out like,
When i first got the frame (only paid 12$ for it)

And the final result: