I think Damon has misunderstood your post. You want 2 discs to show as one, correct?
Importing multi disc sets into iTunes as one disc means that you'll need to edit the album info to show it as one disc. I usually import the separate CDs first, then edit them into one album afterwards.
First, highlight
all the songs from these CDs in iTunes, right click on them and select "get info" This brings up the "multiple item info window". Now go to the "album name" field and retype the album name to one that suits and this rids the "disc 1, disc 2" info that you do not need.
Then you'll need to renumber all the tracks. Start with the first disc and in the "track number field" start with "1 of *, (* being the total number of tracks on
all discs). Do this on all the discs in the set. When you've done the first disc, carry on sequentially with the numbers.
Now, in the "disc number" field you 'll need to enter "1 of 1" to ensure that iTunes reads all discs as just one.
I would also make sure that other info like "artist", "genre" and "year" are the same.
When you're done, click "ok" and all the discs should be read as one. If they aren't, then go back and check everything that you've altered.