Please advise me on a good choice for a tree which I would like ultimately to be the host for 8-12 different apple varieties.

I have become very frustrated trying to manage my Liberty and want to start over. I feel that I need to choose my favorite varieties from that tree, graft over to a younger tree over a two or three year period, and then remove the older tree. (Just don't have room for both.)

Tree must be semi dwarf or readily pruned to moderate size, happy in rocky soil, and hardy to zone 5. Probably best to avoid late-ripening apples such as Fuji and Rhode Island Greening. If I could keep it as a container tree for one year while I get some scions on it that would be nice too.

Disease resistance is a real plus- one of the reasons I chose the Liberty in the first place. Perhaps I should just start again with a new Liberty -we do love the apples- but they have a reputation for being difficult to manage, and I'm not a very skillful pruner.

Thanks for your time and help.

M