I'm definately interesting in going with a 45mm header and mid-pipe, and if possible an equal length system. I have not seen any aftermarket systems available. I wonder if something like a low-mount for a 1000DS motor would fit?
Why would you want a larger diameter, full system in the absence of significant engine modifications? The result could quite possibly be degraded overall performance. Without assurances from an engine tuner that performance can be increased... seems like a big waste of money to me.
Coming from a BMW this bike still has more power than I'm used to. No big engine mods in my future. If I needed more HP I would have just bought a ST4s. I would like new pipes for a throatier sound. I'd prefer oval cans with Ti or CF tubes. I think polished SS wouldn't look good. But, I want to retain the easy to change high/low positions I have with my pannier mounts.
Very positive press from this board regarding Sil's. In fact I have a titanium set of slip-ons on my ST3 with open airbox and I think the bike sounds plenty nasty as configured. But that's just my humble opinion...