Certainly sounds like a fine adventure! Obvious suggestion is to try it out before you go -- photograph with different f/stops. I would be surprised if you would get the results you are looking for at wide open with any lens -- those stars do tend to flare a little at anything besides the optimum f/stops.

If you find a lens in your testing that works perfectly for you, I would suggest noting the serial number and getting the exact lens again for the real thing. There can be some variation between lenses of the same make/model, so why take chances on a unique opportunity like you are planning?!

Vaughn