But if you go for a Bramley, do make sure there are two other trees in flower at the same time for pollination (it is a triploid variety) Well worth it though!
If you have the space, why not plant your potted trees in the ground at your plot, as they clearly dont reward you much in the garden, and maybe add a cooker to them? I rather like Ashmead's Kernel too, a nice russet with an unusual aromatic flavour.. it is also a triploid, but presumable t home was pollinated via varieties on your family tree?
Neither Bramley nor AK can act as pollinators them selves, so at the plot another one in addition to Pixie would be needed, either on your plot or somewhere nearby