Highland Nepenthes have a very well-defined set of preferred temperatures: highs in the high 70s (avoid temps over 85 for extended periods; my greenhouse regularly goes to 82 or 83 for periods, but never over 85) and the night needs to drop below 60F for most varieties. Certain "ultra-highland" species prefer temps closer 45F. If you choose hybrids, especially those that have warm growers in their pedigree, you can get away with nights above 60F, but plants will still respond better if temps drop below that figure.
I strongly recommend you start with a few of the easy plants, like N. sanguinea and N. ventricosa, or any of their hybrids, and any of the N. maxima hybrids, such as N. Miranda, N. Gentle, or N. Ventrata. Once you have grown a few of these easier plants for a year or so with success, you are ready to take on some of the more challenging species like N. hamata or N. macrophylla; those are not good plants for someone who hasn't yet acquired some Nepenthes skills ;-)