I agree with Kal. I think the Twin 20 is fine for your plasma and also a good place for your video electronics (e.g., CATV box, DVD player). I would recommend getting another rack for your audio electronics and locating the turntable on top of that.
Salamander AV Rack
I'm going to need an AV Rack when I add an HDTV later this summer. I will probably get a 50" plasma or Sony SXRD and want it to go on top, so I was considering a Salamander Twin 20 (so as not to put the screen too high), but I am not sure how to deal with my turntable. Has anyone used the pull-out shelves on a Salamander rack? Are those too unstable for the turntable, even if it's inside the rack while playing (pulled out only to change albums)? Does anyone have another suggestion? Thanks.