In order for the tow points to fit with the ARB, a simple modification needs to take place.  The forward 2" of the upper portion of the L bracket needs to be trimmed off.  Here are two photo that show how it can be done. (note: support bracket is visually different than photo, but same exact concept)

Just simply trim off the area that conflicts with the other bumper mounts.  You may even get lucky and be able to put the bumper mount OVER the radiator support.  The ARB bumper is the only one that I've fiddled with fitting along with our radiator support.  I have no experience with other bumpers on the market...but if you send me a photo of how they mount, I may be able to give you a definitive answer.  Worst case scenario: buy the support and I'll give you a full refund if it's in resaleable condition.  If you use it for a while and THEN buy a bumper (and find that they won't work with each other), just stick it on eBay and put a link to the auction on JeepsUnlimited.com and NAGCA.com.  Believe me, someone will buy it!