There are two downtown venues in Oklahoma City with ice plants totally equipped to host the ECHL:
Chesapeake Energy Arena,
'The Peake' (formerly, the Ford Center): IH seating capacity 18,036 - $185 million total cost includes 2010 renovations. NBA Thunder are the primary tenant with leasing rights (reserve dates) to Chesapeake Energy Arena.
In 2004, the Blazers set a single game CHL attendance record at Ford Center of 16,929 in a loss to the Tulsa Oilers.
Cox Convention Center Arena
(formerly Myriad Great Arena): IH seating capacity 13,399 - $55.8 million renovation, June 1997.
Just don't think there is enough ownership interest to bring hockey back to OKC following its disastrous attendance in the AHL. The NBA Thunder currently have 235 consecutive sellouts of 18,203 dating back to 2010. The overlapping of basketball & hockey--especially with OU men's recent sell outs @ Lloyd Noble Center 11,500 may have attributed to that no time table delay to consider bringing hockey back to OKC.
The only minor league development rivalry between Tulsa-OKC exist in USL soccer. Both cities have gone separate ways in minor league baseball & ice hockey.
Sure there are those willing to do hockey in those venues. However, they'll be fighting directly with those venues for dates (The Chesapeake and the Thunder, and the Cox Center with the NBDL team).
From what I understand, the ownership group exists, now it's finding a place to play. Fighting for dates is no fun. The AHL team went tits up because of the way the Funks unceremoniously folded the Blazers with a huge fan base. It made for bad blood and I'm not blaming any of the Blazer fans. That falls squarely on Bob Funk's shoulders.
ECHL is pursuing a team in that market for sure. It won't be next season however.