Wow, that's a big project you are taking on! Glad you are not scared of the scope of what you are planning. The body on CL looks like a pretty good solution for you. You say your uncle "says" it runs and drives fine, does that mean you haven't seen it yourself?
I've done many projects and my advice is to put your own eyeballs on it and do a proper assessment of what it needs and then write down ON PAPER a simple project plan with an estimated budget and timelines that are realistic for your skills and income.
If you do that, you will wind up with a much better finished product and not some cobbled together crapwagon that will be nothing but expensive frustration.
Just my two cents