I also have a TBS with 3-into-3 pipes and use the Cortech Sport saddle bags and tail bag. They are not the biggest bags around, but I was able to pack enough for a 5 day trip including rain gear and laptop.
I sometime use the tail bag alone for daily commuting, though I prefer using my Bailey Works messenger bag. The tail bag goes on and off quickly with four built-in bungee hooks. I can easily fit a couple folders, laptop, pair of shoes, and assorted sundries.
The bags are on sale (slightly) at New Enough Street Hard Parts -
LINK
(I have no affiliation with New Enough, but have had good experiences ordering from them.)
Enjoy,
Rob