I just picked up a pretty mint pair of older legends but with Solomon c509 bindings which don't appear to be a good binding. Any thoughts on a good replacement without breaking the bank? Thanks in advance.
Almost any binding that meets DIN standards and is currently indemnified by its manufacturer should be good enough. There used to be a public list of indemnified bindings; now you have to call up a shop and ask. Go to dinsetting.com to figure out what your number is. The general advice is to buy a binding with a range that you'll be in the middle of.
Aside from that, it's a matter of preference. Aside from the KneeBinding, none of the bindings has much claim to any more safety than others. Anecdotally, some bindings seem to release a little too easily (older Markers) and some seem to stay on better (Looks). All should keep the forces transmitted to your boot under the "safe" threshold.
If you do replace your bindings, you'll now have two sets of holes in the skis. That's not a huge deal unless they end up too close to each other. It does somewhat weaken the ski and reduces resale value.
I'm your size and have some 8000s in 172. They're really a nice all-around ski.
The Marker Motion bindings on Supersports are "system" bindings and will only work on that ski because they need the built-in rail. I have a pair of Supersport Allstars and that's the way they are. IF the Legends are flat on top, you can use any binding except system bindings. If you're looking for a bargain, check out the clearance section at Level Nine, they always have some bargains. Or try Ski Universe. I got some Head railflex bindings from them at a ridiculously low price.