check out dirt website they have a review/advert/vid thing about some steel hardcore HT , there are a few companys that do burly steel dh hartails. I would personally choose steel as they are more forgiving due to the nature of the materials. Be prepared for sore ankles tho ! I had to ride my hardtail for a few months between DH bikes and my ankles took such a kicking , gotta wear a support/compression on one now , i'm a pretty smooth rider too but some times you gotta get rough to be fast ! ( or just plain get it wrong )
If I was you (and I've been there) I'd be looking for a Sinister Ridge or Evil Imperial. Both great frames, I had a Ridge and sold it as it was too big to use daily. It's Aluminum too so massively stiff. I ran it with Boxxers but tried it with 40's and it ran great and was still quite a steep head angle so no risk of pulling it off. If you can't find either then search eBay and the such for FTW's own version of the Ridge. (He made them for Sinister and then after he left for his own company.)
Here's a lift of amazing hardtail frames. The chromag frames ( mainly the stylus). The transam by transition. The commencal absolut al frame. The gt ruckus hardtail trail frame. The cove stiffer and handjob.