Jeff, is there any reason you couldn't put one together from a kit? Would be a simple case of following the instructions, throwing some components on the board etc, a heap easier than trying to design a coil from scratch around your own components.
I say this because it'll allow you to build the coil how you like, in terms of enclosures etc.
If you look closely at that first creepy eBay coil, I can see parts scattered all around the base of it, even looks like a MOT there, no idea what you need that for in a SSTC.
He has a "microBrute" kit for around $300, includes basically everything you need but a fan and an enclosure. You get the satisfaction of building it yourself, without having to design anything. Bear in mind though, it's still a high powered solid state device, and you probably will pop a few components before you get it running correctly. Tesla coils aren't really a build and off you go affair, although with a kit, it's going to be quite reliable.