Your setup will be fine. The only reason that mine doesn't have any (big) gaps, is because I used 50' of 1/2", and I wanted all the coils in the wort - including 5G batches. You can see my build at :
http://www.wortomatic.com/articles/Mylo ... -O-ChillerI did just "enhance" it's design. I pounded a 1/2" rigid copper pipe flat, and bent it into a ring, that I soldered to the bottom. This makes a better seal with the bottom of the kettle, and serves to hold back most of the hops (obviously some still manage to get through).
Mylo