I wouldn't do the rack when your planning on getting one snake. It doesn't make much sense, it would be like bringing a semi-truck to deliver a letter. If you think this one snake is going to turn in to multiple snakes then I would go for it. If not, then a rack will be pointless for you.

Also if you are getting the snake as just "a pet", a lot of people like to see them and look at them in there enclosure. This is not easily done w/ a rack system.

Just some things you might want to think about before you dive into building a rack.