Unfortunately, small touring bikes like the silverwing (The name is now used for a maxi-scooter, but used to be the lightweight GoldWing for those who haven’t seen one) are pretty rare right now.
webBikeWorld ( http://www.webbikeworld.com/motorcycles/kawasaki-versys/ ) has been doing lots of reviews on parts to turn a Versys into a lght weight touring bike. And I think BMW makes a couple of 800s that work well for touring. None of those will be in your price range though.
Going used you are pretty limited. BMWs hold their value for a long time, and the Versys is too new to be that cheap.
Most likely any 600cc UJM (Bandit 600, Honda 599, etc) should work. I don’t know enough about cruisers to make any recommendations there.
Try looking at dual sports though, the KLR650 in particular. It has been aroudn 20 years basically unchanged until last year. It is very reliable, has no problems on the freeways, and has a following who use it as an adventure-touring bike (ala BMW). Several companies make comfortable long distance seats for it, though some people say the stock one is good enough for all day riding.
While the KLR650 produces more power and is more top heavy than your silverwing, it is supposed to be a very friendly bike.
I think a number of people on this forum own KLR650s, maybe one of them could chime in?