slim pickings for DT's in this years draft, Marcus Spears being the best package of character, experience, leadership, size, speed and athleticism who might still be available when the Texans select. I could see the Texans try & trade up to around the 10 spot if Haloti Ngata declares his intention to enter this years draft (Payne is due a big FA contract) but seems unlikely at this point the Texans use their first round pick on a lineman, defensive or offensive (most of those are also staying in school).
I think it boils down to either a linebacker, safety, CB or outside chance of a RB if one of the big names fall. IMO