I'm considering spending the winter in tinkering and building up a road bike (unless New England should miraculously have a warm and sunny winter this year). My main objectives in order are:

1. To learn the mechanical aspects better (I only do minor repairs and adjustments now)
2. To have a bike to experiment with (e.g., compact crankset, etc.)
3. To have an alternate bike

(My current bike is an R600, which is fine in terms of quality/performance so far based on my abilities). I'd really like to be able to make something fairly decent (i.e., I'd like to be able to climb with it, so not sure about an old steel clunker) and that uses current technology. I don't mind spending a bit more than it would cost to buy a pre-made bike, but I'm sure I'll have my share of screw-ups, so on the other hand, I don't want to start out with anything that's really high end that I'll destroy in the process. I have no time constraints.

Would I do best with just looking for a aluminum frame on ebay? Are kits worthwhile? Where does one find them? Suggestions welcome - I have a few vague ideas, but not sure where best to start.