Don't know if you've tried Tunica, MS yet. There's a big cluster of hotels in that area geared for the casino industry. Its about 45 miles south of d'town Memphis on US Hwy 61. A bit of a drive, but it sounds like your options may be limited at this point.

What ever you do -- DO NOT get a room anywhere in West Memphis, AR. This area is a 100 square mile truck stop and is completly the pits.

Anyway, Good Luck.