I just found out about this project two days ago. And minutes ago I finished reading all your posts. I felt like I was watching an action movie and all was lost when you made the no go post, I almost cried lol, but then I read 14k price, basically gold.
LOL!
To answer a couple of your questions, I don't think you can make a profit building and selling a custom/kit car UNLESS you build to order--i.e. get paid for your labor and the customer pays for all parts up front. Build a car on spec and buyers will beat you down by claiming they'd have wanted something built differently.
Engine brackets for 4g63 would be included with the kit.
Total car weight is estimated at 2500 lbs. and yes to air conditioning.
JR