I don't know if this is any help but I found very early on that the plastic mounted Solo Seat rear rack was far from adequate and had to remedy it to carry a true touring load.
I now have two configurations - the small OE rack for around town and short trips.
And a larger rack for long tours carrying 40+kgs.
Both have customised pillion pads which make it truly a two-up tourer -- though with minimal luggage.
If you are looking for a saddle bag option check out Davorallyfan's setup.IMO the best set up if you want panniers.
For my set up the key is modifying the sub-frame and welding on an additional cross-brace along with four upright mounts.
