SS/Fire or Dark

I know that SS/Fire is an extremely good end game farming build but my character concept fits Dark better. Is it just as viable for farming end game? I know it has more endurance issues and the rez/heal are target dependent but just wanted to see if anyone has any experience.

Do you mean SS/Dark or Dark/Fire?

SS/Dark or SS/Fire.

SS/Dark is a terrible combo.  Both are quite strong separate but together they will kill your blue bar.  Endurance is already an issue with /Dark as it has no way to regain endurance or mitigate recovery outside of slotting more end reduction.  On top of that it needs 4 toggles to get your resistances to hold/stun and immobilize plus the damage aura.  Considering most brutes endgame shoot for as high of S/L resists and defense which means tough and weave in addition to careful IO slotting.  On top of being toggle heavy, the one heal in the set will kick you in the teeth for 1/3 of your endurance (before slotting).  The good news about Dark Regeneration is that the heal portion is so OP that with no slotting for heals, if it hits 3 targets, you heal from 10% health to full so it is best to slot that for end reduction and recharge vs recharge and heal.  Now combine that with rage crashing every so often and likely hasten as well and you end up chewing through the blues like candy.  Now once you get to 50 and can get your Alpha slot, much of that can be mitigated, but the trip there will be tedious.  Fire on the other hand has only 2 toggles on top of the damage aura and has consume to get your endurance back and a self heal as well.

Of the 2 choices, I would go with /Fire first, use that one to farm up some money for all the Heal and Stamina +recovery and + endurance procs as attuned enhancements and then level the /Dark. 

If the only concern is endurance, then you should definitely go dark if that's more thematic for you. Every problem in dark armor has very easy solutions. For the aoe heal, just slot the theft of essence +endurance proc. Send yourself some cash from an alt and always have that slotted. In a standard mob you'll go from eating up endurance to completely refilling it and your hp in a single move. Alpha slot is not needed to make dark armor viable for endurance heavy primaries.

Omg I totally forgot about the theft proc. Great advice.

I played an SS/Dark brute to death back on Live. It's amazing. Yes, you do have to dedicate yourself to addressing the endurance costs, but: 1) this is highly doable, and 2) the results are spectacular.

If your goal is to be an endgame beast and your concept favors /Dark, then go /Dark.