Advice on Single Speed frame wanted

Hi Team,

I'm posting this on behalf of a mate who's asked me to help him find a good SS frame. He's a serious rider who's unfortunately been bitten hard by the SS bug for many years. He's been riding Specialized Stumpjumper Single Speed which was pretty good for him but he's recently snapped the frame so needs a replacement.

What's the collective wisdom on a decent 29" SS frame that won't break the bank (ideally less than $1,000), preferably in steel or Ti? A Sir 9 was looking good but they have a bit of a reputation for breaking, this needs to be solid as he puts the bikes through a lot. He's not keen on the idea of custom Ti from china, too much of a gamble, which rules out a few options.

Any other ideas from the collective or something amazing in the shed you want to unload?

thanks in advance
d