If you cannot march a DCI corps this summer, there is another option: DCA/All age corps. There are now 3 DCA drum & bugle corps in Texas. All-age corps require less time (generally 2 weekends a month) and money than DCI corps, but the educational value is quite comparable.
For example, a 2 year vet of the Frontier brassline is likely about to become the youngest member of Madison Scouts this season. He's 15. He had no marching experience (he doesn't march in his high school band), so he knew nothing about marching/playing before Frontier.
DCA/All age corps are definitely something to check out.
Austin Stars, in Austin (www.austinstars.org)
Gulf Coast Sound, in Houston (www.gulfcoastsound.org)
Frontier, in Dallas (www.frontiercorps.org)
Frontier's next rehearsal is December 16th (location TBA--check the website soon.) Check the other corps websites too.