Get the four burner. I have had a five burner for over six years or so and never replaced the burners. I love the IR so much I would not be without a CharBroil IR grill. Cleaning ain't the problem one would think. As an experiment I went over six months one time and never cleaned the grill or emmitters and had no problem at all.
I have measured temps of 800* plus on my grill.
Granted, it may not have the quality of stainless steel as others but if it did it would cost a whole lot more.
I strongly recommend you get it and a good cover if you don't have an overhead cover. You won't regret it. Also,if you can buy an SRG you will have bought the McGiver of cookers. That thing is amazing and TMB can do things with his the inventors never dreamed. With these two cookers you can do everything but "low and slow" ; however you can still smoke and get great smoked flavor on butts, ribs, poultry, and anything else you want to cook.
Dee