what telephoto options beyond 200mm for nx?

I have read back over the threads about the rumor of a 300mm nx lens, but don't want to wait indefinitely unless someone has a any sort of release date.

I am not adverse to using a mount adapter and understand that it will mean manual focus and aperture, and a tripod. I have a m42 adaptor and have played with my nx300 and old lenses and didnt find it difficult to adjust, but they were not high quality vintage lenses, nor long.

I don't think a mirror lens will suit me, as I am after sharpness.

This may be a really dumb question, (be kind) but are there any lens in the 70-300mm (or 400mm) range that have a built in stabilization that will work with an adapter on the nx mount, or does image stabilization always require an electronic connection to the camera? (IOW, do I need an oly or something that has in-body IS?)

Let us pretend that money is no object (ha!) is there any way to accomplish this, or do I need to delegate my nx to wide angle and go with another camera for long shots? if this is the case, are there any aps-c systems that have a longer lens? IOW, how long can you go with an aps-c camera (with any lens configuration?)

I understand the argument that if you want long, you should go with a full size dslr, but I am a small person with small hands, and the diminutive samsungs suit me so nicely, plus I find the samsung image quality (to my taste) above others. (and money, is of course, always an object)

Thanks for any advice.