Well, I dunno about the 'not too light thing', my S540 is considerably lighter in weight than my 2 RGs(my GF commented that it was light enough for her to play lol)
The newer models with the "ZR" trem might be a bit heavier, because the bridge has extra hardware and seems to be of a weightier design(if that makes any sense). I'm still trying to get used to having it hanging on me, it feels like there's no guitar body there. lol
As for necks, most of the S-series guitars have the Wizard or Wizard II necks, depending on the model. There are a few with the "Ultra" neck, but not many(it's a bit thicker, but still smaller than a strat). Basically, just razor-blade thin, with the Wizard II being a little thicker. This is back to front though, the nut width on these is pretty wide, @ 43mm(1 11/16"). I'm sort of addicted to the Wizard neck now, after playing one for so long, BTW.
As for actual models in your price range, you're gonna be much better off buying used of course. I would personally stay away from any of the past Korean models that don't have the ZR trem(in other words, ones pre-2003). The older LoTRS trem is rather crappy, IMO. Anything with an Edge or LoPro Edge trem would be damn good. You might want to look into the S-Classic series as well, if you don't want a tremolo.
I'd look for a late 80's early 90's model, probably an S540FM since you like the flame tops.
There are deals out there if you can find them, I bought my S540LTD off the Harmony Central classifieds for $310 shipped.
Tone wise, I think these sound really good, the body gives the impression that it would be a thin sounding guitar, but it's not.
Not real fat either, like some full-sized mohagany guitars can be. I can't get too in detail to the tone of it yet though, because the stock pickups leave a bit to be desired. lol
Whew, that was long-winded for me..
Hope this helps.
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