99 Legacy wagon stereo upgrade

I've got a 99 30th anniversary edition wagonthat has the two-piece stereo -- radio/tape in one deck and cd player in the other. I'd like to take them both out and replace with a single receiver/cd player. I've got a couple of concerns though:
1) the radio antenna telescopes up and down when the radio is on (it goes down when the cd player is active). Any issues connecting this to an aftermarket cd player?
2) where can I get a trim kit to cover up the hole that will be left when I take two components out and only put one in their place?

Thanks for your help!

hey man if you get the wiring harness to 'plug and play' your new radio or make sure to keep the remote power wire and you can get all the fillers and everything at circuit city or places similar that sell adio accessories