I would say with that money you coud go for Carbon Fiber FS bike. And the best option is for sure 27,5". Check out Trek and Scott. If you go for 26er, then look at Specialized. Check some bike with brain.
I understand you don't feel well with 29er but whay don't you try a HT in M or S Size: I got a Trek X-Caliber and it rides very well in all kind of terrain...
You might get two bkes: one FS and one HT.