bro if you ask me, just cut the visible fat you see in the meat and you'll be ok. Steak has a lot of fat in b/w layers of meat that you can't take out, so just take out the ones you can see.
LB is a pretty thick cut, it's available anywhere here in the US. Not sure about The Netherlands jaap. But because it's usually cut pretty thick, a GF grill wouldn't work unless you sliced it up yourself first. I'll either bbq it or broil it.