I'd go for LF - it can be end heavy, and I found it very much to be just that until I got Stamina.
I have Stamina 3-slotted for End Mod atm, and even now, when my SO's are yellow, I find my End dipping low-ish.
Mind you, come Power Sink at lvl 35 all your end problems are a distant memory 
Early on I recommend having your shields on permanently (NEVER drop them) and only have LF turned on in the middle of a large group of mobs, which helped me early on kill some of them before I had the chance to get around to them.
Now however I tend to run it all the time in missions, as it helps keep aggro and helps build fury (albeit indirectly by keeping aggro on you).
With Lightning Field 2-3 slotted for End reduction and Tough with 1-2 End reduction you should be ok - if youre L40 at the moment then you should have 3-slotted Stamina and a 5-6 slotted Power Sink, so youve got more Endurance to spare than most brute builds (my /Elec has had the least End problems of my 3 brutes).
I actually run 6 toggles on my Fire/Fire brute, including Tough and the damage aura, and Power Sink recharges a lot faster than Consume does, but I still get by fine - it only becomes a struggle when I get End-drained (by Mu, Sappers or Spec-Ops), but /Elec protects you from that anyway. Also Fiery Melee primary is also generally more End-efficient than Energy Melee primary (which my /Elec brute has) - for the single-target stuff anyway - so I cant see you having too many issues.
Hi,
i have another question concerning my Fire/Ela brute.
I have now fixed my build until lvl40. From level 41 on i
might get lightning field and / or tough in addition to aid self, which i took earlier in this build.
The question is, do i get already end problems when running 2-3 shields and lightning field ? Can i use this only from time to time?
If i add tough also, does power sink recharge quick enough that i can fill up the end bar again ? 3 shields, LF + tough might be a little to much or is it still playable ?
Thanks for any advice.