I play a 7 piece set with 5 toms (8/10/12/14/16). What I did was set the 10/12/16 up just like a 5 piece kit. 10 & 12 on the bass, then the 16 in the traditional floor tom position.
After that, I placed the 8 to the left of the 10, and the 14 to the left of my hi-hat (ala Dave Weckl). It's just like playing a 5 piece kit (comfortable), but with more options.
Just an idea, but it all depends on how you play. Spend a weekend doing nothing but different setups. Set the kit up, then play for 20 minutes to an hour & make small adjustments. Before you know it, you'll either have a comfortable setup, or you'll at least have some direction for what WON'T work, and you can go from there.
If i had your setup, I'd probably center the 10/12/13 toms over the 2 bass drums. The 2 16's, I'd put right/left like mine are, or both to the right if that's what you're comfortable with.