Fire/Fire is indeed squishy, mainly because /FA generally requires mitigation help from the primary, which Fire/ doesn't offer.
SS/FA does not have this problem. I mean, compared to say SS/WP or SS/Inv, SS/FA is still squishy but all the KD, (especially Footstomp), works wonders for /FA. Being able to knock an entire spawn on their arses every 5-10 seconds is really helpful in giving Healing Flames time to recharge.
SS/Elec has better resistances and esoteric protections, (end drain, psy, toxic in the Godmode, etc), but the heal recharges much slower and has a +regen component.
I personally am not a fan of /Elec because of Grounded being screwy, (no KB resistance - just protection so high mag KB will throw you around, only works on the ground and doesn't work on all surfaces), and generally not being a fan of how Energize works.
I never found it to do all that much for my survivability. What /Elec really shines at, and I mean really shines at, is endurance management. Energize gives you a 60% (I think? Someone correct me if I'm wrong) endurance discount and once you get Power Sink you'll never have end issues again. Power Sink is also pretty good at draining in conjunction with Lightning Field.
They're both strong combinations so you shouldn't be discouraged by my personal dislike for /Elec, I just feel SS/FA is a stronger combination.
Oh, last thing to note. SS/Elec having much more rounded resistances and protections means it is generally more reliable while leveling up, especially in the 40s where you face a lot of psy damage, drains and debuffs.
Depending on how much you're willing to spend on the character and what you're using it for, I'd recommend different things.
For farming/high budget: SS/FA
For overall leveling/low-medium budget: SS/Elec
Hope that helps 
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The Melee Teaming Guide for Melee Mans
FA has a faster recharging heal, but in return Elec offers higher resistances across the board, no psi hole, end drain immunity, 20% extra recharge, a sizable regen component on the heal, much better endurance management and a godmode.
The choice is clear for me.
I have a ridiculously IO'd version of both of them, both built with unlimited budgets. If your sole interest is dealing damage and making stuff die I'd recommend /Fire. If you want more general use I'd recommend /Electric.
Hello all out there I want to roll a new brute and I have been struggling between to sets. I have played a fire/fire brute before and it felt a little on the weak side, so I thought I would try Ele. My problem is that when I look at the mid numbers they look pretty close. Ele wins if you use Power surge but other wise it looks close. So I am asking the wise people what if ant advise would you give. I also don't mind hearing form the not so wise. Thank you