Get the smallest saddle bag avaialble, put that on then push the aquarack up as high as you can.. I had this set up for the last 3 years. Minimalist saddle pack had only 1 tire lever, 2 co2s, microinflater and multitool and a glueless patch kit.

I would carry extra tubes in my bento box or shirt pocket on training rides. I would tape them to the seatpost during races.

here's the bag I use. the mini wedgie pack.
http://www.specialized.com/bc/SBCEqProduct.jsp?spid=25161