I would just pop in LEDs deep blue will have the least impact on pythons in general (other snakes may react differently as do most lizards) LEDs that can be plugged into walls (110V-220V AC) produce about 90ºF-95ºF surface temps. Most FL lights produce around 95-100ºF surface temps. (you can quickly check yours) the blue leds over night have little to no impact on pythons (they don't see much blue end of the spectrum). I would expect a drop in ambient over night but much less dramatic than you are currently seeing. It is easy and very efficient.

Radiant heat sources have little to no direct effect on air temps so adding radiant sources (Radiant heat panels or Radiant heat tape aka flexwatt, aka UTH ) will not solve the problem with out mucking about with thermal mass and heat syncs.

I use something along these lines... This is just an example the prices are wildly variable so poke around some.

http://www.ebay.ca/itm/Blue-57-LED-A...ht_4013wt_1280

They are very bright so I found that pointing them away from the floor and I have used plants to obscure some of the output.

Fast Cheap and simple.