I wouldn't go with either, scratch machbusters are real cheap (+- 20) and you can make em whatever diameter you want. I would do with 38mm and adapt down for flying 29mm g-h motors, i don't know if there are any 29mm I's? Then, when you feel crazy, shove an Ellis J in there and get yourself a walston, that thing should break mach. Whoosh-bam-pop.
Yea... But! If you already have the nose and some bits of plywood laying around the house it becomes a 4 dollar tube as your only expense.
Or, if you really want a kit, I would say go with the aspire. The bigger motors you can put in a 29mm tube the better. You can out an H in teh Aspire f you really want to see it go mach and at least 6k.