sounds like you have your driver built you have identified your diodes. next thing you will need is your test load so that you can tune your driver to the appropriate current. a 1 ohm resistor with 4 l4101 diodes(think that is the right number should do the trick.)
here is a website form another member that is really good at telling you how to use it.
It can be done - Laser driver
I built mine on perfboard with leads coming off from the appropriate places(to make it easier to test) I used 6 diodes so that I can test for both blue and red setups. as blue (3-4+ volts) requires a higher voltage than red (approx 2.7).
I am not sure how much current you will want to push to your diode I bought a red one on ebay unidentified that I pushed at 190 no problem.
the flexdrive is a wonderfull little guy (I mean little) is very stable has a low dropout voltage compared to the standard lm3117 in the ddl driver. btw the lm3117 can be replaced with a lm1117 (summin like that I should be pretty close) which requires less voltage thus you can generally power everything with 1-2 volts less that the lm3117 driver and the pinouts on that regulator are the same I believe as well.
dr lava is generally pretty good at getting the current right where it needs to be as well so you should have some pretty good luck there.
infrared will generally show up kinda red to the naked eye as it is quite close to what we see as red in the electromagnetic spectrum (and may kick out some from the band) be aware however that although it just looks like just a low powered red it can be quite dangerous. most of its power is in the IR area of the spectrum thus not visible.