hi I_reese_ii, we are also going to sing+malaysia this december, you can try check it out online sa mga hotels and airlines, so far cheapest is Cebu Pacific around P12000, then hotel grand central hotel (P5500)is good since naa sa orchard road but naa pa pud cheaper ha, padung malaysia either mag plane mga P3000 or train around P1500, then city tour sa malaysia(think via taxi nalang) then go to genting highland overnight.
computed for a singapore+malaysia around 35,000(hotel and airfares lang) a bit expesive though kai december peak season.
If not there's travelosicty or try
Fortune Travel