Well, even with that kind of soundcard, I doubt they'd sound anything like the real thing. The only way you could get them to sound exactly like the real thing is to use an extremely good (yet expensive) sound library while making the song with midi code, and mix down to AIFF and WAV (and MP3 if you want to share it over the internet).

I actually downloaded one of the lower quality models of the symphonic orchestra from East West QL. (You can see a sample I made in Writers Corner; Interupted by Fireworks, or check out this quick sample I made for the quality here).

But if you look here, here, here and here.

You can see some extremely awesome, real sounding songs that were made specifically with each pack. I'm currently trying to download the RA one, but it's 15GB's. The others are around 40GB's and I don't even have that much space left on my computer. ,_,

I know Nik0tine was incredibly impressed, especially with the chior pack where you can actually type words for them to sing, and get that quality.

Note: If you're a real composer/music enthusiest, you'll check out those links.