Toyota: Help in buying CD player for 2000 Corolla CE

Hi,
I just bought a used 2000 Corolla CE which only has a cassette deck
and radio. I want to add a single CD player to it so I have both CD
and Cassette.
I would appreciate if someone would help me out with the following
questions.

1. The cassette player already comes with CD controls on it, so is a
Toyota OEM CD player the only one for which those controls will work ?

2. Exactly where on the dash can a CD player be fitted so as to add to
the Cassete player and not replace it? I can't see any empty slot that
could take the CD player. I looked at the OEM CD player available at
http://toyota-parts.com/partdetail.asp?PartID=897&ModelID=960&SubCategoryI D=38.
Can that one be added to my cassette deck? If so, can anyone recommend
a good shop in the Sunnyvale/Santa Clara, CA area to install it at a
reasonable price?

3. Is it better to go for a non-OEM CD player for any reason? If so,
which are the good ones that can be installed reliably on a Corolla ?

4. Is there any particular place in the Bay Area from which I can buy
and have an OEM or non-OEM CD player installed at a reasonable price?
Are Circuit City or Best Buy good options?

These are a lot of questions. But I do hope I can get them answered on
this group. Thanks very much in advance.
Rahul

Check out www.crutchfield.com -- good online source of gear.
Why not add a multichanger remote deck? Tend to keep
theives from smashing glass and ripping your dash apart.