I found another deal for Bali, from London now with Philippines Airline. More dates available just for February. It’s not the best deal I’ve seen so far but still a good price. A plus is the short transit time in Manila.
Try http://www.booking.com for bungalows rental in Seminyak area, one of the best in my opinion for tourists. Or try http://www.airbnb.com as I’ve seen great rooms there. The daily expenses are relatively low so the flight is the biggest line in the budget. No need for vaccines there but have a travel insurance, a home insurance also to stay relaxed, and really pay attention to drugs as there is a death penalty in Indonesia.