Well with IOs your SS/FA Brute can take on large spawns. Most Brutes willl build for recharge with FA as it gets Healing Flames back up as quick as possible. Also Footstomp will be recharging quicker and the knockdown in itself is very good mitigation. So building with sets that have recharge bonuses in them is usually a good idea. I have a 50 SS/FA that can run most farm maps and I recently respec'd him so that he ended up with about 35% S/L defence. I haven't fully tested this yet so can't really give back a full report. However I know building for nice amounts of recharge with sets such as Crushing Impact and Obliteration is a solid plan.
I hope that helps,
Tux
Well you want to load up on Kinetic Combat IO sets for def in single target Mellee, then focus on recharge time.
Gratz on lvl 50. 
Now a question for you: Did you take Tough and/or Weave from the fighting pool? The Fighting Pool is fairly often taken with Fiery Armor to help with its survivablilty. Some people will even go as far as saying it is necesssary.
So, when I planned my Fire armor brute, I looked for +recharge, +HP, and +defense.
I have Tough and Weave on my elec/fire brute. I do think Tough is required on him to make him survivable, but I was surprised how much I noticed the difference when I added Weave. I only have CJ to stack with it right now, but I could tell a difference. Now I just need to get some +def sets to really make a difference.
I just dinged 50 with my SS/FA brute. I know jack piddle about IO sets and what-not. I just ran a farm with my VG with a billion dudes in suit's named Jack Werp or something. My fellow Axe/Invuln brute was able to pull 2 groups sometimes with little trouble, however if I was in the vicinity of one of their farts I would fall over.
Can I eventually look forward "through IO"s to be able to survive even one group's alpha without falling over? Or do I just stick to the fire brute farms?