I think being a vegeterarian is the best thing for calorie counting and Indians! I always get a vegetable curry because it has much fewer calories- and I get a chapati too because they's got far fewer calories than Naan bread!!
I'd personally just ask the waiter which curries have cream in i.e. a Korma DEFINITELY does and avoid them. But you can get some lovely veggie kinds which have excellent seasoning and flavour without all the oily-creaminess! Good luck Oh and I'd save about 600 calories for the food itself just to be on the safe side!