I think you should go ahead and build it! And, if like me, you decide you don't care for the 20" pipe, than build or buy a bigger one! I will be converting my 20" to a grill at some point.
Butts, MAK n Que BBQ Team
Smokin Horns BBQ (private parties)
MJH by Backyard Bombers
Cajun Fryer FF2
Weber One Touch Gold 22.5"
2006 Keystone Hobbi 220 Toy Hauler