I'm even lankier than you are at 6'7" and other than a single flight in a 150, I did all my training in a C172.
I did, however, do a few hours in a Piper post-PPL, and never - never - got used to the idea of having to clamber across the seats to get in.
It wasn't a high- vs low-wing argument for me there are just not enough doors on the Piper for my liking
As others have observed, it's obviously a very personal thing so have fun trying them both out.