I just finished my setup using
this adjustable stepdown-converter for solar-powering my usb-hub and
this converter for solar-powering my raspberry.
[img]http://ecx.images-amazon.com/images/I/41QFsBHeCcL._SX342_.jpg[img]
[img]http://i.ebayimg.com/t/KIS3R33S-DC-DC-7-24V-to-5V-3A-USB-Power-Converter-Buck-Module-/00/s/NDY2WDcxNg==/z/x9oAAMXQCtlROcPy/$(KGrHqJ,!q4FE1DPDNBEBROcP)2(7!~~60_12.JPG[img]
Running three Block Erupter USB-Miners along with the raspberry and the hub I am running at 0.8A.
Pretty cool!

You've obviously gone to a lot of work for all this, I'd love to see some pics of what you came up with in the end. Like panels/battery/charger etc. Maybe put it in the mining hardware pic thread (130+ pages thread)?