hell if i know!!!! just kidding. whatever mods you do, i'd recreate the effect before installing. such as you could get a minijet (a small paint sprayer) and mist ink onto some different substrates, then hovering halogens judging distance and feed and such to see how the ink behaves. or preheat those surfaces with a hair dryer and then mist to see if you feel the ink drys better being printed onto a warm surface. with the halogen you have a heat and dwell time issue. it will have to dry very quickly or else you will experience dot gain on low dyne substrates.
the rheostat is a great idea. also...the youtube video had a crude lamp fixture. i'd wire a series of those tiny halogen bulbs in a small row, maybe three or four of them.
more compact more surface area. AND when you do install that bank of light, configure some kind of lamp height adjustability.
i'd imagine installing a pre and post lamp would be best. the preheater would be on the left of the print head very very close to the surface. the post heater on the right with more of a flood. also get one of those silocone heating blankets to experiment. they are really cheap and would make for an easy compact reheat on the back of the printer.