If you are over six foot, I would strongly recommend you get either extra legroom seats, or premium seats, which can be pre booked.
Some of the Thomson long haul jets provide a better seat pitch than either virgin or BA in economy. I'd really suggest you look at extra legroom, as ALL airlines really cram the seats in in economy, and usually charters are worse. This is especially important for longhaul.
Don't say you've not been warned!