^^ Always take everything on interwebs forums with the caveat that what we say is usually JUST ONE PERSON'S OPINION. And those opinions often differ. I qualify what I say quite often but sometimes I don't; but, really, that should be a given.

You really don't need to do anything drastic (IN MY OPINION). I personally would lose the big ring, put a nice bash guard on and maybe go up to a 36 middle ring anyway. Since you're building this, take the opportunity to customize some of your build to better suit the way you're going to ride it.

More info on chain wrap on the late Sheldon Brown's web site which you may find some comfort in:

http://www.sheldonbrown.com/harris/derailers-rear.html

See his note about capacity.