The one thing I can tell you about most of the sewing patterns available in most fabric stores is that they aren't long enough in back length for whippets so need adjustment to the pattern there and after a
I did find out there was a sewing machine called a WHIPPET http://forums.about.com/n/pfx/forum.aspx?tsn=1&nav=messages&webtag=ab-sewing&tid=13172
I know none of this is of much use to you however. I would think since you are not a sewer you might want to consider a beginners course and get out the tape measure and start measuring your pup and make adjustments for seams, body length, depth of chest etc.
Good luck on the project, and let us know how it goes. Perhaps some of our sewers will jump in with some advice soon, I'm on the East coast and just now up at 6AM.