It should fit, it's a std. double din sized unit which is the same size as the 97 deck w/ the pocket or cd player attached. I'm not sure what kind of brackets you will need to find/use.
You'll also need a harness and have to do a little work with the wiring, since they changed the connectors in 98 for the 6th gen.
Good luck finding one, it is a bargain to get one under $200 on ebay, and my local dealer told me $1400 for a new one. I just got one for my 98 EX-V6, will finally get around to putting it in this weekend.
Also try to get the code from whoever you buy it from. If not though its not that hard to get, as long as it doesn't look like it has been ripped out/stolen they should give it to you, all they have to do is look it up, most won't charge you if you bring in the radio yourself.