I have a couple of small ARRIs frenel (350 & 650) for when I need focused light and I use off-the-shelf halogens for back lights or colored accents.

My main lights are these cheap ass things that I love from a company called Kool-flo. It uses daylight balanced compact fluorescent bulbs that put out the same light as Kenoflo Diva 400s, BUT, for the cost of a single Diva you can get a 4 light kit of Kool-flos. They take a little more time to set up and break down but well worth the trade off in cost.
I like these lights because they put off very little heat and they draw very little power. I can plug several light stands into the same outlet and not trip a breaker. Each stand draws a little over 200 watts and puts out a 700 watt equivalent but they rarely get too hot to touch. Certainly never the blistering heat of halogens or metals.
The drawback with fluorescents is they don't have a very long reach but that's usually not a problem on most porn sets.

The daylight balanced fluorescents are only about 100 degrees off from natural sunlight (depending on the time of day) so light seeping in from a window doesn't interfere with my artificial light sources and I can use them for fills on outdoor shoots.

I went to Lowe's and bought additional compact fluorescents right off the shelf for 2 other common color temperatures so if I go into a set location (like an office or a warehouse) that already has standard fluorescents in place, I can match them from my kit; and it cost less than $200 for all the additional bulbs as compared to the $85 each for the Kenoflo bulbs (4 bulbs each stand).

With accent and back lights I don't worry so much about the color temperature. A little color shift in the background makes no difference. Just make sure your key and fill lights (and c-light) are all the same.