Turns out that these use basically the same driver as the more expensive ones that use a 1 watt pump diode. So, I edited the information I gave you earlier because it was wrong. These fastech modules use a 500 mW pump diode and if you don't have a bench power supply that can read the voltage and current you are using, you can use a fully charged Li-ion battery and measure the current going into the module with a DMM and adjust the pot so it doesn't draw more than 500 mW. My mistake.
Ok yep ill do that. If you know of any other modules Im happy to have a look but Im hoping not to break my budget of $40-50 (35 for the host and battery charger etc) yes I have a DMM and I have some experience with soldering.
Any other suggestions for design or better options would be appreciated (as always).
Edit: Ok something has come up and I have to delay the build for a few weeks. I will get it done though and might ask a few more questions towards the next few weeks if im a bit unsure.
Should I start a new thread when I finish the build?