I looked at Factory 5 about three years back and initially liked what I saw, but then the more I looked the less I liked some of their "innovations". What really turned me off was that when you really look the only similarity to a true '33 is the grille. The other body lines have been tweaked, some more than others, and that tall space frame that you have to step over to get into the car didn't work for me. Another was the removable hard top - lines didn't work for me, and that gasket space? I'm too much of a traditionalist in the "looks" arena. If you're truly doing a show car I don't see the Factory Five getting you there - it's a purpose built car, and the purpose is road course style driving.
I kinda like the American Speed 33. All steel, but roll up windows and a convertible top are cool. It has a "traditional" look, or you can go with the stylized grille, etc, if that's where you want to be. Brookville? About as bone stock as you can get, right? Good quality, and do what you want to make it yours. I had not looked at the Kugel Mirage, but it's got some neat features and Kugel is top notch. I especially like the 3" longer cockpit & doors which is nice for a tall guy or gal - a Deuce design with good proportions, IMO.
Keep us in the loop on your plans. Any build is a good build!!