I've got the "Dwarf Everbearing" mulberry but the fruits have always been seedless, as far as I can tell. It could be that I lack a pollinator, or the seeds are so small that I've never noticed them... I'll have to dissect rather than eat my next ripe fruit. They are easy to start from cuttings, but those are harder to ship internationally.
If given enough light, the dwarf everbearing mulberry does very well as an indoor plant; they take pruning very well and can be kept at any size you want.
Kevin