For the overflow bottle, maybe just 8-12 inches of 2" or 3" round PVC with an end cap on the bottom end, and screw-on for the top. Drill two small holes in the top cap, and push the overflow hose in one of these until its near the bottom. If the white color clashes with your sano styling, then bust out the black paint.
Can fit pretty cleanly against black tube frame and nearly disappear.
Were you still using the OEM style lead-acid battery? If you can spare the change you might look into a LIFO replacement. Prolly save about 7-8 lbs and these are tiny in comparison, can be mounted sideways, and of course your bike will be faster and get like 200 mpg. (JK)
Just spit-balling ideas ...