Agreed -- that's just a trim piece, not a fork brace.
I'd say just don't worry about the fork brace until you're completely out of things to spend money and time on.
I'll let you in on a secret -- I ride like a bat outta hell and have 97,000 miles on my GS850G, and I don't have a fork brace yet. I've always found better things to spend money on, somehow. Out at the ragged edge, yes, the fork flexes a bit and I could get some benefit out of a brace, but I've never felt unduly deprived:
Here's the Tarozzi brace:
http://www.fastfromthepast.com/servlet/the-587/Fork-Brace-Suzuki-GS850G/Detail
The stock shocks are complete crap, and you can't get replacement springs or rebuild parts for them anyway. When the time comes, Progressive shocks and springs start at about $200+. There are also some Chinese-made shocks available for around $80 under various brand names (Emgo, MDI, etc.) that aren't too bad.
You don't need to replace the forks -- simply make sure they're working correctly, with good springs, correct preload, and fresh oil in them.
Overall, you've got the basis for a nice bike there. If I were you, I'd make a list and prioritize. You've got a couple of months before it thaws enough to ride much.
For example, first get it legal (registered and insured), then get it safe (new tires, front suspension), then get it running flawlessly (valve clearance check, new carb o-rings, new intake boots/o-rings, seal airbox, address any jetting issues, deal with any oil leaks, etc.).
In the process, you'll learn a lot, you'll uncover any remaining issues, and you will sort out the next steps on your own. You might decide you don't like the handlebars, for example -- that's a matter of personal preference, and you just need riding time with the bike to figure this out. (The bars that are on it are probably OK, actually.)
Overall, it's far better to get it running and working right before you decide you need to change a bunch of stuff. Since you can't do or buy everything all at once, prioritize and take things in stages.
Most people who complain about GS850 performance simply need to fix their bikes. Bone-stock, a GS850 is certainly no GSXR, but it's damn fast and very satisfying.
Somewhere on his site Basscliff took a rant/list I posted a while back and turned it into a checklist of the steps involved in achieving GS850 Nirvana.