It would help to know more details:
- what you found dissatisfying about the tank version
- what you mean by underperforming as a brute
- what you mean by underperforming at tanking
As you're just using generic IOs right now, you might be hitting some End issues, as neither SS or Inv have any built-in way to boost recovery. I would suggest putting the Miracle or Numina unique(s) in health, and the Performance Shifter proc in Stamina.
For toughness, make sure you're slotting up Invincibility and Tough Hide for Defense, and Weave from the Fighting Pool if you're taking it. IMHO the only skippable power for most builds in Inv is Unstoppable (though some people respec out of Dull Pain after getting incarnates and all their set IOs). Other than that, at least one Resistance IO in RPD, RED, and RND, and at least two Resistance IOs in Temp Inv and Unyielding.
For damage, getting Rage double-stacked is very nice but might be hard with just generic IOs. It should be perma at least though. Fully slot your bread-and-butter attacks (Footstomp, Knockout Blow, Haymaker) at the very least.