Have you published before? Does the agent care if it is in the 'right' format? I have the dummies book on publishing but I haven't tried all the tactics. IE, getting a well-known to endorse it, etc.
I decided to take the bull by the horns and do it myself.
Had a lot of help from friends...and I would recommend having several friends proof it...and then when you are sure you have it perfect...do it again with some different friends. I had several sets of eyes looking at it independently and some errors still crept in which my customers pointed out and then I fixed as I went along.
Put out Five individual volumes that way...each one well over 400 pages. And then did a large hardback edition which contained them all.
Best of luck. It's certainly not easy...but it is a lot of fun.