Hey Tom, welcome to the board.
You may be interested in checking out this fly fishing club- I believe they're near you in Jackson:
Magnolia Fly Fishers
A club is a great way to get up to speed, meeet new friends, try out gear that belongs to other members, get casting help, local where to go what to use info, and participate in group trips to local or far off waters.
The 6 weight is a pretty versatile weight. Finding one rod to do everything can be a little tough-- the 6 is a good compromise for both panfish and bass, and would also be a decent freshwater trout rod if you do some of that in AR. That whole area is a world class trout fishery and a lot of guys on the board fish there a lot.
I guess there are a couple ways you could go. Getting 2 6 weight outfits for you and your wife is one way. But if your wife is a little less enthusiastic than you are, you might also consider getting two different weights that are close enough that you could still fish together for stuff, but are different enough to be better at some things. For example since you already have a 6 weight you could get a
4 weight- panfish would be a blast on this light rod, but it will be tough casting bass sized poppers. It would be considered a small stream small fly fly rod for trout.
5 weight- this is more or less the ideal all around trout rod, also would be fine for panfish and small bass sized flies, just a little less oomph than a 6 weight.
7 weight- less suitable for panfish and trout (more of a trout streamer weight for large rivers) but would be better at throwing larger bass sized stuff than the 6 weight. Would also be suitable for light saltwater (reds and specs), but overkill for panfish.
8 weight- this is a FW bass weight for throwing large bass bugs, and is also a great light SW weight for the Gulf. Overkill for panfish and trout.
(All this assumes she'd let you use 'her" rod when she wasn't fishing. This may be a fatal flaw in the master plan.)
If I already had a 6 weight and wanted to add another rod I'd probably add an 8 weight in terms of versatility, mostly in targeting big bass and SW, and using the 6 for trout, panfish and small bass if you think you may be fishing alone a lot. But if the goal is to get your wife interested and fish together that may not be the way to go- maybe two 6's or a 5 and 6 or 6 and 7 would be better to keep the peace.
If you're bidding on a used Winston, try and make sure you find one with a blank warranty card. You may also look at a Sage Launch it should be around the same price range (new or used), and ideally it's always best to actually cast a few rods to see which one you like--- although that's getting harder and harder to do as small fly shops close all over the country..