Howdy Ninedd,
If you have an AP card that works but is too low in power.
Have you considered a power amp as a temp solution until nirvana gets here?
Of course it wouldn't work if you needed the power on the CPE side also.
I am only using 5.x with WLM NX200 radios (FW 4456) all sites in the -60 range.

Good luck,