Here's the deal. The sfv end can is not good

And I just don't like it, I want to put a 'proper' can on there.
Problem is the options for the SFV are all fairly pricey when all I want is a cheap aftermarket can. (slip on not full system)
I know s...t about this so was wondering what my options could be for getting a cheaper can (one for an SV?) and fitting that. What makes the slip ons model specific, is it simply the link pipe/connectors?
Anyway any help/advice would be great. Otherwise I'll just have to put up with it til I have enough cash to stump up for what's on offer.
Cheers