re: the NiteIze upgrade. This uses a voltage boost circuit, so it would not be a good idea to install red LED's instead of the white ones.
The high output red LED Kingbright X-Brite W7113SEC/H from Mouser, rated at 10,000 mcd, has a Vmax of 2.8 volts, which would work with 2xAA NiMH's, but would be over max rating with alkaline.
The Vishay 78-TLCR5800 looks interesting. 20,000 mcd, 8 degree illumination angle, Vmax 2.7, but the wavelength is a bit short at 616 nm typ.
Radio Shack has high intensity 5mm red LEDs, 3,000 mcd rated at 2.4 Vmax. Again, it may work with 2xAA NiMH's but would be really overpowered with fresh alkalines.
All of these are T 1 3/4 packages. The focus ability won't work with most LED's anyway, as they will project light out in a beam rather than to the sides like the standard bulb.
I'd like to try the Kingbright, but it isn't worth paying shipping for just one LED. Maybe I'll try local electronics suppliers.