collision damage/exhaust question

[bluextc]

Ok, so I posted before that someone hit my bumper (and exhaust tip). I have a $500. deductible, and the estimate was for $1000, which means I have to make some decisions. The major factor is whether the body shop will be able to replace only the damaged tip/muffler, or both. Does anybody know if they will be able to buy just the one flowmaster muffler or will they have to replace both? Because if they can only replace one, I'm going to just leave the tip damaged for now (it's minor), since I'm planning on getting new tips in 2 years when I get the car repainted anyway, and I will get a bumper from bumpers.com and put it on myself and not have to pay the deductible. If they would have to replace both mufflers, I'm going to pay the deductible and switch from the Flowmasters to Mac Flowpaths, and get the bumper done nicely (they are even going to paint the mustang letters, instead of the vinyl letters). Any help appreciated, and also, any experience/opinions on the flowmaster to mac switch?