Tours and Passes in London

[trevor_schofield]

I'm planning on spending a week or two in London in October and was wondering if "Great British Heritage Pass", "London Pass" or "Original London Sightseeing Tour" that are offered through Britrail are worth checking out.

Also, I was looking at getting a 7-day London Travel Card, but was unsure if service to just zones 1-2 is enough to do sightseeing in London, or if there is a need to travel out to the outer zones 3-6.

Any other advice on sightseeing and getting around London for about a 2-week period would be great.