I've not seen a double-barrel exhaust specifically for the SV.
It wouldn't be a huge hassle, or enormously expensive, to cut down the link pipe on this Devil system for the R1
http://www.ebay.co.uk/itm/YAMAHA-R1-...item45fd115b0c
An exhaust fabricator could make up a custom link pipe for the SV. Just find the local place where the car lads get their systems made up.