I would suggest flying into somewhere like KL in Malaysia, Air Asia flys from London they do have good deals. Then from KL you have Asia at your fingertips. Once again Air Asia has some good deals, just keep checking their website.
The route I would suggest is Thailand via Chaing Mai to Laos down the Mekong to Luan Prabang then onto Cambodia, Vietnam.
Or start and just go until the money runs out. But do not book any thing other than your flight from UK as we found it is cheaper inside these countries. We booked a 3 day trip from Phnom Phen to Ho Chi Minh city (Saigon) for 50 US for us both that included hotels and transport/tours. We Bussed, river boated and bussed through the Mekong Delta then up to Saigon, brilliant trip. Aussies on the same tour had booked it in Australia before they left it cost them...from memory about 150Aus . Our most expensive hotel in Vietnam was in Saigon $22US per night for a double room with bathroom ,a very nice room with TV and AC. Cheapest was in Cambodia at Siem Reap $8 for double room with bathroom. we did this trip in 08 so prices may have increased. We are among the older backpackers around so like to be reasonably comfortable.
Enjoy beaches in Thailand at Krabi nicer and Cheaper than Phuket also other coast of Thailand but havent been there also beautiful beaches in Vietnam..China Beach etc. Cambodia also has a pretty bit of Coast in the south.
Eastern Europe,Bulgaria, Macedonia,Albania, Bosnia, Montenegro, Croatia, also a good and reasonable trip we did all by bus.
Happy travelling.
Edited by: naej