Silver lining I suppose is you can buy it back and get it repaired at a place you trust.
It'll always have that cat marker on it though, so will be worth less when you sell it on.
For the hassle, I would just get another...
A quick search
http://classifieds.pistonheads.com/...-civic-mk6-type-r-2005-premier-edition/999793
You'd get some money off that, and then you'd be straight back in a 'straight' premier. Seems a no brainer to me
I'd repair if it was mine. Won't cost THAT much and then you have your car and not some other pup which you don't know the history of... Depends if you still want an EP3 or if it's time for something new...