Depends what set you want to run.
Thick Fat will complement a defensive Rest/ Talk set, which means Hariyama would be a phaser (so run Rest, Sleep Talk, Fore Palm and Whirlwind). You could also go defensive and run a Bulk Up set, then Rest for 2 turns and return to sweeping, or do Bulk Up, Rest, Sleep Talk, 1 move. Then again, if you did that, you might as well go for Guts since the Sleep Status will activate Guts.
I would actually suggest Guts over Sheer Force. You might not take damage from Life Orb if you had Sheer Force, but if you're burned then your entire set is useless. It's the same with Conkeldurr in OU. Both are so slow that they're prone to status moves.
Additionally, Guts increases attack by 50%, while Sheer Force only increases moves with secondary effect by 30% (ignoring the secondary effect). While you do get added Life Orb no recoil damage, Hariyama doesn't have a lot of great moves to use for Sheer Force. The only viable move is Rock Slide, the other moves either being too weak or special moves.
Brick Break's power does not increase from Sheer Force. See here, that's a list of all the moves that will benefit from Sheer Force.
If you ran a Guts moveset, there'll be wider options for Hariyama.
Hariyama @ Flame Orb
EVs: 252 Atk, 172 Sp. Def, 88 Speed
Stone Edge/ Thunder Punch
Watch out for Pokemon like Weezing, which will be able to Pain Split wall you.