multi-variety fruit trees.

so, i have some whips to plant at the farm, a peach, a pair of early apples, and 3 sweet cherries. i have a mature montmorency in my yard, as well as an italian plum that gives me no fruit . (did some root surgery this winter. fingers crossed.) i will add a few more later this year, probably 5 year olds. i plan on about 20 altogether, mostly dwarf, or dwarfed by pruning.
i am thinking i would i would like to add a large multi-variety apple. or maybe a plum. really looking for the mid-future crop while i wait on the whips.

have seen a few apples in common varieties, but i would really like to get some of the more unusual apples out there. one good for drying, particularly, and a good pie/canner. a good eater, of course. (room for a single or two, but...)
pretty much same would go for a plum. i love plums. just that apples keep better. plums likely wouldn't make it that far, tho. (so you see my problem.)
i have kept quite a few things way under budget so far, so i could splurge on this tree if i could find just the right one. gonna call a couple of the local good greenhouses. but would like opinions of varieties, and on the concept.