I agree with E'pin about the TV selection - but the trick is getting a chance to really evaluate them on a level playing field. Have the LG dealer let you take in a disc you are familiar with (Blu-ray would be ideal, but DVD can suffice) and let you adjust the display from the standard show room "torch" mode to a more accurate setting. Use the remote yourself, figure out what you think of it - both in picture quality and in ease of use. Try to do the same at Sears and Best Buy (although you'll likely be stuck with whatever the store feed is for picture, you should be able to get the remote and start exploring). I haven't heard anything about the LG 50PG20, but
here is a review of the 50PG60 .
As for the setup, there's no problem using HDMI for video only and then running audio (be it digital or analog) to a receiver. I've been doing that for quite some time now with the Model 990 and several HDMI sources.