I love the look of the IRIS. 1/2 or 3/4 scale is a much more manageable size, IMO. I have been amassing parts for a 1/2 scale. The nosecone appears from the drawings to be a 6:1 ogive, which isn't readily available commercially. Of course, you can fudge it with your paint scheme and it doesn't look at all terrible.
I just don't have the space or muscle to deal with a 20' rocket. Propulsion becomes a challenge as well. Of course, there is always the notion of a team project, which can be fun.
I say gofer it.
--Lance.