I'm not a rajah major but I grow mine in a chunky loose mix of orchid bark pieces, LFS and charcoal. I'm doing an experiment with some rajah plants by adding Laterite (Fe) to the soil of one plant and Flourite (Fe , Mg, Ca) to another to see how it affects the growth, leaf/pitcher color, etc. but all the pots are "loose" and drain f-a-s-t! I water them thouroughly about twice a week nowadays, more often in summer.
Make sure your plant gets a lotta light and cool temps at night (50-60*F) YEAR ROUND. For me this meant building a vent from the AC and humidifier to the terrarium and hooking up a thermostat and humidistat so the tank gets cold at night and stays very humid at all times. This time of year I simply have a 4" fan sucking cool air from outside toprovide chilling on the tank. In winter I will take air from the surface of the closed window which will bring the temps down plenty as my windows need to get that plastic draft guard anyway.
My terrarium is cooler in the daytime now (only to 70*F) and my highland plants seem to be picking up speed with this temp which is 15*F cooler than they temps they were getting in mid-late summer.
Keep humidity 80%+ with bright light to get reddish hued leaves and nice pitchers. People say it can take lower light but I've put all my "lowlight" neps in bright flourescent or compact flourescent light and they always do better with more light, at least when it's artificial light. The rajah and other highland neps are getting 280 watts of FL/CPFL about 14 hours a day.
I hope you have plans worked out for cooling the plant before you receive it as it's the most important aspect of highalnd neps stayin alive. Running the cooling gear in summer aint cheap unless you like in an alpine climate-so be prepared! I could order a lot more utrics, sundews or lowland neps instead of paying these heinous electric bills! Too bad highlanders are so much cooler than anything else plant like on earth!