Zorf
Continuing with the custom build solution, I'll second/third that. I've built a full-out large scale (9 piece Eames birch), 5 piece mini kit, numerous snare drums, and most recently, a nice ol cocktail kit:
http://www.cocktaildrum.com/gallery/sho ... isbach.jpg
I gotta say, I'm not all that handy either! But if you've done any craft wolrk you'll do well if you take your time and dig it
Will offers a very nice and flexible design that could work either way. I actually have such a kit (16x16, 9x10, 10x12, 3x13) that is a subset of my main studio kit. While I don't stand up with it, the kick can be used vertically or horizontally with spurs.
Nesting is another thing altogether though. An alternative to nesting shells is to use a multi-tom bag (I have one by beato) or a conga case. The shells aren't nested but several small drums can be carried in one 'tube' container.
Regarding the GigPig, I've only heard the samples from the site and they sounded line tradeshow floor recordings, so everything sounded well, boxy. The idea looks novel, and it's cool that they are basing the idea on the cajon, however, I can't imagine that it could/would really sound as versatile as a cocktail kit (ie 2 or 3 separate drums). Take a look at Peter Lau's designs on this site. OMG....I wonder if Peter has any patents on his work?? There's a short clip of Peter playing one of his 'BoxTail' designs and it DOES sound really good (so does his playing), so maybe there is something to this idea of a multiple-chamber box drum......