what do I upgrade?

Not to be repetitious but I would also go with dedicated lines first, you're happy with your Red Dawns?--stay with them, if not you can certainly do better, then, power conditioning. I'm a big Audio Magic fan, but you can do Shunyata, Sound Application, and others, as well. I treat my electric as another component. Those three steps will give you electric nirvana. Your system will thank you for it. peace, warren

My first thought is the Red Dawn may give the 'light' sound you speak of. Of course YMMV. It seems to be average cable for such a nice system.

I agree with the posts above, dedicated circuits and power conditioning, including room acoustics. I would add high quality AC outlets such as the cryo'd Porterports sold here on Audiogon (one of my favorites).
Secondly, if you changed your interconnects you most probably will hear a big difference in what you stated you wish to improve. I have been most impressed by the interconnects and speaker cables made by Ridge Street Audio. They work very well in my tube and SS systems.

Dedicated circuits: if you had done this to begin with your upgrades would have been more enjoyable along the way, AND PROBABLY NOT HAVE SPENT SO MUCH - BASICS FIRST!!

I spoke with several electrician and don't think dedicated circuits will help since I live in brand new home in a newly developed area. Is this true? Also, what power conditioner should I be looking into?