Troy,
Good advice here. For the time and effort it will save you, having the frame powder coated and the body bonded to the frame is well worth it. There will be plenty of work left for you to do, having ERA do that part of the job is money well spent (IMHO)
Another option would be to find a completed 289 and start from there. Allen's 2124 is a great example of how a car can be personalized when not starting from scratch.
Best of luck with your project!
- Tim