Advice needed. Newbie looking to do a restoration right

[finaltable]

In High School a friend had an '86.5 MkIII so I decided back then that I want one. Two decades later I'm ready. I have a trusted mechanic with whom I will be working on this. I currently have a '96 Camry he works on infrequently :-) and this guy knows Toyotas, though he told me he hasn't worked on that many Supras. This will be my 3rd Toyota, a Corolla having preceded the Camry.

The facts:

The look I want is the '92 Targa with the integrated spoiler. It must be standard transmission. While the non-turbo engine had plenty of performance for me, if I am not mistaken I have to get the Turbo model to get the integrated spoiler. This car will be a daily driver and my current employment requires that I drive about 100 miles a day. My time frame is "as long as I need." My budget is roughly unlimited in comparison to what this will cost (it is actually in the several thousand dollar range but I find it very hard to believe it will cost me that much to do this.)

As part of his repair business my mechanic also buys cars at auction, fixes them up and sells them. He goes to auctions all over the South East US to find cars.

I want to ask him to start looking for a MkIII for me. I plan to replace the engine/transmission if needed, brakes, other mechanical parts as required until I have what is essentially a "new" MkIII. The one part of the car I can't replace, however, is the body itself so I need to focus on getting the best platform with which to start.

This will not be a car purchased with an eye toward performance, in fact, if I do have to replace the engine I am thinking about putting a naturally aspirated one in instead of a turbo. Long term reliability is a major goal as I would like my 5 year old son to drive this car someday (if oil doesn't run out first. ;-)

I need to know a couple things before I start this:

Is the Targa top a problem?
Are there any areas of concern about the bodies themselves that knowledgable Supra owners know are common in the MkIII as it ages?
Is there anything else about which I need to be concerned before I start this process?
Any estimates on the cost of a decent platform given that I don't care about the condition of the engine/transmission?

Thanks for your help.