I've never had the mindset that white wine is for chicken and fish and red wine is for beef...
Salmon isn't overly delicate and can stand up to a heartier wine, I wouldn't serve a burgandy with it -- but since you've got the balsamic vinegar in there, as well as butter... you really want something to stand up tot he flavors) BUT PLease no Merlot... thunderbird has more flavor.
I'd probably look at a pinot noir... This is a pretty good description of the wine... and it ranges anywhere from 7 dollars a bottle (for stuff that's good) to over 50... the cheap stuff is just as agood as the expensive stuff.
http://www.winepros.org/wine101/grap...iles/pinot.htm
Sangiovese is also another nice red that's just starting to get some attention that would go well with salmon
http://winepros.org/wine101/grape_pr...iovese.htm#top
If your partial to a white wine - then i'd go with a Pinot Gris or Pinot Grigio - which is the white wine cousin of Pinot Noir... it 's a light and refreshing wine it's a little delicate (but doesn't have the awful aftertastes that most chardonneys do) and may not hold up to the balsamic vinegar and butter flavors - but it won't overpower them or conflict iwth them...
http://www.winepros.org/wine101/grap...pinot_gris.htm
best bet- ask the professional working in the wine shop... or if they sell wine int he supermarket, like they do here in hell, there are usually tasting notes near each varietal -- the tasting notes will give you the aromas and bouquets -- just kind of use your imagination as to whether it would go well with your meal...