Hope you've got reeaally deep pockets, because the BotZ -KB alone--which, BTW, Invul does *not* need--will probably cost you 100 million inf.
Your power order and selection is pretty good, though I'd take Tough Hide as soon as it's available. Either ResEl or ResEn can be delayed to make room for it.
For tanks, the benchmark is soft-capping with one foe in range of Invinc, by that metric this build does hit the soft-cap for S/L with CJ toggled. Be warned, though, that some pieces of Kinetic Combat are currently very expensive and hard to find. Putting together 3 sets will be a challenge, so if you're using Boxing primarily as a IO mule, consider using the KD proc in place of one of the other enhancements. And note that the attacks that are four-slotted with KC are underslotted for Acc and Damage, so I'd recommend adding another slot to Haymaker at the very least.
6-slotting Touch of Death is a very expensive way to get 1.88% S/L def. I'd use 4 slots of Smashing Haymaker instead, which has the same bonus for a fraction of the cost. SH has the same problem as KC regarding Acc and Damage, but if you add an additional slot you'll still have a free slot to use somewhere else.
As I mentioned above, the BotZ -KB is very expensive and absolutely not needed for Invul. And since F/C damage is the least common other than Psi and Toxic, I'd pull that slot and use it elsewhere.
Again, F/C def should be a low priority, so instead of 5 Scirocco's in FootStomp, I'd slot 3 Eradication plus 2 Scirocco's, which will give you a nice E/NE def bonus.
Both Weave and Tough Hide are very underslotted for defense, an odd choice considering that you're buying expensive IOs to get defense bonuses. I'd put 4 slots in Weave and 3 in Tough Hide. While any defense set will do, I prefer the bonuses in GotA and LotG over Red Fortune. Something to consider, anyway.
My Characters
Knight Court--A CoH Story Complete 2/3/2012
Hey guys, i was browsing the tanker forums the other day, and read up on invuln, and how much it loves defence, so i took a rough guess at my brute, and tried to soft cap it. Im thinking i may have overkilled the defence, and underkilled the damage, but i wanted some advice on the matter. Lemme know what you guys think.