Other than the laptop, you don't mention what's filling out that Tumi laptop brief so it's hard to make a solid suggestion, but I'd imagine you can go down to one bag for overnight trips.

Unless there are physical limitations that would prevent you from carrying your bag, I'd be looking at the Tom Bihn Western Flyer or (if more room is needed, though I can't imagine it would be on an overnighter) the Tristar. Both fit in the overhead of a CRJ, and -- unless something crazy happens -- you will likely never be asked to gate check. Both can also go under some seats when needed. In a dark color, both look professional enough to hand- or shoulder-carry to a conservative client site as a computer brief with the benefit of being able to go full-on backpack if needed to hoof it through the airport.

There are lots of folks on the Tom Bihn forums willing to enable your purchase and also help you maximize use of space in your bags. (I would post links, but my darn iPad erases this post each time i move to a new window, which is annoying as heck.)

Hope that helps.

Rgustafs