Dude, that's a killer budget. Firstly, just for full disclosure, we are very pro plasma at AH. Secondly, I have a problem with calling those LEDs, because only the backlight is LED; it's still LCD. I remember the first time I saw a Vizio ad for TruLED. A more apt name might be FalseLED. Just because my LCOS based projector uses a mercury lamp, I don't call it a TruMERCURY projector. Do you call your RPTV a Mercury TV? Sorry for ranting, lol.
Secondly, you can actually afford the Kuro KRP panels for the pricing they've been had for many months. The only question if you can find any at this point. The 500/600M are the same panel as the 111/151/141, all of them with different feature sets. The most important thing the KRPs are missing is the ControlCAL ISFccc, but you can actually get a patch for that.
The V10 G15 G10 S1 all use the same panel. From there, certain things like consumer level pic controls, THX mode, OTB performance. If you even got the cheapest S1, and had it pro calibrated, it's very likely to look identical to even the V10. However, two caveats. I think that 24p playback without 3:2 pulldown on the V10 only is certainly worth something, especially with how big you're going, but $1,200 gets pretty hard to swallow there. I cannot say for certain, but I am strongly led to believe that there will be video processing differences, if only going by what I saw with the previous generation.
The last thing I want to throw out there is if you've ever considered a projector. You can get a Panasonic 4000 for $2k, which is LOADED with features (or the Epson 6500 for a bit more), and is a serious sweet spot value. For the time being, you can use a $250 DaLite High Power screen to pulldown in front of whatever TV you have, perhaps a 42" S1 for, say, $700. Total is then $3k. If the HP screen ever disappoints you, just start saving up for a tab-tensioned screen, but more likely at around $2k, depending on the final size. Just something to chew on. I still have this nagging feeling that even most AHers have no idea how good PJs have become, for very affordable prices.