William,
I concur with the general opinion- a used replica will save you several thousand dollars while you decide what you really want. Kirk's base price on a VS is fantastic, but many "extras" are just that- extra. If you buy a really nice used car, it may very well cost the same or more than the base VS, but come equipped with lots of options that would really drive the price of a new car up. If you've never had one of these cars, its really hard to know what you need and what you don't
Before I had a replica, I couldn't imagine owning a car of any kind without A/C- I thought I really needed it (it gets hot here in the summer- and humid). Once I had a speedster with no air, I wondered what I was thinking- I really wouldn't want it. You can be reasonably certain that you don't want the base 1600 cc, single carb engine and drum brakes, beyond that you really have to own one for a while to get the feel for what is desirable to you. Some guys want all kinds of original looking stuff, and the kind of carpet bindings and dash knobs start to make a big difference, some guys really don't care as long as it works well. I thought I was in the second (don't care) group with my first car, but quickly started becoming a "retro-grouch" after less than a year. I really care now about all sorts of arcane stuff that I didn't even know existed before I bought the first one, and didn't care enough to buy when I had my JPS built (10 slot wheels, wide-5 bolt pattern, under dash unbrella-handle e-brake, etc.). Stuff like that costs money- you'll never know if you want it until you have one.
The point is this- I'd get something with enough options that you can tell what you need/want and what is extraneous before you have one built. Unless you are a guy like Bill Steele and can build the perfect car right out of the chute (and nobody else is- you're the man, Bill), I'd do it this way- you can get a lot more for your buck buying used. Then build the car of your dreams after you've had the car a few years and know what you want. Good luck.