Well, in response to your question I see a great deal of time and effort has gone into the car. I like the idea of FI, I have it in my garage on a shelf awaiting time to install it....
One thing I don't like is having the FI electronics out in the open so to speak. A lot of dust, oil, road debris, water when it rains or you wash the car, and the like circulates in this area, at least on my car. Also, I tend not to like the ebay presentation model these folks use...too many photos that really don't tell you much other than 10 views of the body from each quarter a few degrees apart.....
In regards to conversion to wide 5's if that is what you want to do, there are rear drums that will accept wide 5's available for about $50 per axle (rear only) Wide 5 disks can be fit on the front for about $500 if you do the work yourself....and those are available in "0 offset" so you don't make the clearance worse on the tire to fender. This car in ebay you linked to appears to have "short axles" in the rear, which gives you a bit more space to play with, however the wide 5 drums might require machining about .625" off the snout of them to fit short axles as I best recall, mine did. I am not certain which wide 5 drums came with a short axle car.....