You currently have a 4 into 1...so, you can't use a 2 into 2 because that will leave you with 2 exhaust exits with nothing on them. I'll assume that you mean 4 into 2, in which case yes, you have a few options. Check out the MAC 4-2 exhausts for a start.
Alternatively, you might be able to find an old set of 4 into 4 pipes, if your bike is the K model (I think). This might need to be confirmed by someone with more knowledge than me, though.