John,
I've been through that learning curve a bunch of times. One of the values of a forum like this is to share experiences. If I may, please allow me to share a few thoughts as you move into digital.
Were I you I would not start with a newly introduced camera like the Sigma and Foveon sensor.
You should look at something proven to start with.
(I should've taken my own advice concerning the ND). A Canon D30 if you can find one, or a D60 if you can afford one. The only lenses that fit on a digital camera that can compete with Zeiss glass are the Canon L lenses, and a few select Nikon primes. I learned digital with a D30 and can attest to it's performance. It is an extremely easy camera to get along with, with very intuitive controls (the D60 is the same camera with a higher meg count). It uses a CMOS sensor which consumes power very frugally. It is also small and light. The canon 35mm/1.4 L lens is the best 35mm SLR lens currently available IMO. Their long lenses with IS are unbeatable.
Another route you can take if you must have that Zeiss look is to buy a high end 35mm scanner (Canon or Nikon with 4000 dpi ability), and just keep shooting film. Use any funds saved to improve your image processing equipment ( like more memory for your computer, PhotoShop 7 and Genuine Fractals to make larger prints). Then there is the printer...latest greatest is the Epson 2200. Best out there currently IMO. These items will make more of a difference in the final result than a few extra meg in a digital camera. A 35mm neg scanned at 4000dpi produces a image file as big or bigger than the $8,000. Canon 1Ds digital camera. $8,000. buys a lot of film and processing.
Finally, even consider a higher end P&S digital to get your feet wet. The canon G2 or 3 has all the controls that my Pro SLR has, just not interchangable lenses. It's a really inexpensive way to learn digital, and you can always use the P&S for family snapshots and travel images, (go to this forums' general, all camera sister site, then click on Gallery, search fotografz, where I've posted some Las Vegas travel shots taken with a lowly Canon G3. I think you will be suprised what it can do).
Good luck with your first steps into the future of photography.