Bolivia - flights from London and itinerary advice

Hi all,

Having been bitten by the travel bug on a 9 month trip, I have managed to get work to give me a month's holiday at once in May/June. I'm planning on going to bolivia, but I was wondering if people knew the cheapest way to fly there (and back) from London? Is it better to go to continental europe for a direct flight?

Also, any suggestions for a 1 month rough itinerary would be much appreciated.

Kind regards

Chris

La Paz flight maybe via Ecuador, Lima, or even BBAA or Santiago.
Internal flights are cheaper & overland travel (from say Lima) gives an opportunity to get used to altitude.