This is what I use:
http://www.mpja.com/XL6009-Adj-5-35V-DC_DC-Boost-Converter/productinfo/31397+PS/They also have one with a built in meter:
http://www.mpja.com/Boost-Converter-Adj-4-35V-with-LED-Meter/productinfo/33525+PS/I know it doesn't make sense for you to order from an electronics supplier in Florida, but I would imagine that you have similar suppliers there. Mine is added as a boost supply, to make a standard PC supply, useful for my bench. You might consider adding one to an R/C Li-Po battery or USB power bank.
