Mmm, dunno if I'd bother with the Lifting stunt. With PL 10 super-strength and 20 strength, your light load is already 50 or 100 tons.
Durability isn't so useful if you've got protection as your main defense. It's better if you have amazing save-damage.
Immunities are swell, pick them up, some people even put them as extras on super strength or con, you'd end up with 10 of them at 1 point apiece.
Penetrating attack has been errattad, check greenronin.com for the MnM erratta. Basically it was broken before (allowed exceeding the PL cap), now it's no longer useful at all, just max out strike or super-strength. I'd like to see it get fixed and be useful, because I think it's kind of a nifty concept, but right now ignore it.
Attack Focus, Power Attack, and Takedown Attack are no-brainers for a brick.
Stunning attack, it depends on how he'll be fighting. Since it doesn't add any stun hits itself, it's not so useful if he ends up fighting by himself against a team. If he'll have some backup who can help take advantage of a stunned target, then it's swell. Combo it with surprise strike, he can do a power attack/stunning attack one round, then power attack/suprise strike the next if the stun worked and possibly take someone out of the fight in two rounds, especially if they had a force field that went down when they got stunned. With rapid strike and a high BAB, he might be able to do it in one round.