Any light the emits in the UV-A, 315nm - 400nm, range should work very well for alternative processes. Moving into the UV-B range may give you additional benefit with shorter exposures but is not worth the risk associated with UV-B and/ or UV-C spectrums. UV-A specturm is not something to fear if respected and and you do not look directly into the light for extended periods of time.
A metal halide @ 400W and with a Kelvin temperature above 6500K should be sufficient for contact printing, the hight the wattage the further the lightsource can be away from the print.
For those that are interested in reading more details on suitable light sources for contact/alt processing printing I definately recommend taking a look at Sandy Kings excellent article at the Unblinking Eye - http://unblinkingeye.com/Articles/Light/light.html