All the Tier gear in the game has a rating! so just make specific OPs that require a certain level of gear to have a gear rating lvl, for example Columi has a rating of 136 so if i have overall gear rating of 600+ then I'm allowed to queue for EC HM via the group finder.
Gear checker won't weed out a player that lacks skill. Skill > gear.
It's so easy to farm black hole commendations and get gear, you could have people queuing for HM EC with a super-high gear rating that had never set foot in ANY op and need more experience before running it.
I've seen a black-hole-geared dps fail his assigned Infernal Council member (timer reset and Luthro had 41% health left). I've also seen someone in recruit gear main tank all of HM EV.
The original idea posted on this thread is that higher level ops are "unlocked" by successfully completing lower level ops -- that is a much better solution.