If you know how to talk to shop guys, they'll do damn near anything. If you piss them off, they won't give you the time of day using your watch.
Bend up some Tig filler wire (Get it from your shop pal) into the shape you need and take it to the exhaust shop. Try not to piss them off and they'll bend it for you. (Leave enough excess on both ends to ease the fitment.
Since they're trying to make a living fabricating exhaust systems, try to explain that you need the pipe to do something that their company won't allow them to do or that you're too broke to afford a shop to do the whole deal.
Sorry im not quite getting what your saying? Im supposed to get wire from my shop guy and bend it to match my stock pipe? And then bring it somewhere else to get the 3 inch pipe made? I really dont want to piss off my shop guy because he does everything else on my Jeep and he knows my Jeep well. I dont like bringing it to tires plus, dealers, etc because you never know if the person working on it knows Jeeps at all or was just hired.