I have a 70's Yamaha 335 style electric 12 string with the stock pickups. They tend to underperform compared with my other guitars and I'd like to replace them but I'm unsure about what will provide a strong clean tone. Reviews tend to mention some as more bassy but I'm dealing with a somewhat different sonic arrangement being 12 string. Any suggestions from someone who thinks a lot about pickups to someone who hasn't really until recently? I'm leaning towards Gibson's 57 classic Plus for no good reason but the seem to be a simple solution. I'm also concerned about feedback as I've been playing at higher levels than I used to. Are most pickups sold potted?

Thanks,
dustin