If the mpeg files are already compliant to dvd-video standards, then you can import them into a dvd authoring program like DVDStyler and get a finished dvd. DVDStyler will also reencode them if they are not compliant, but in that case, I would use AVStoDVD instead, since I prefer the HC mpeg encoder that it uses. These two programs are free to use.
Both can produce a dvd small enough to fit onto a blank single layer dvd without having to run it through DVDShrink. The output will be about 4.3gb, which is the actual amount of data you can put on a nominal 4.7gb dvd.