Well today I decided to stop asking and start doing! After almost 3 months of reading various threads I'm armed with enough knowledge leached from all you great builders. I have no EPP foam at the moment so I went to a few local building supply shops and found some 3/4" EPS rigid foam insulation under the brand name of "PlastiSpan" at Home Depot. A bag of 6 sheets 3/4" x 14.5" x 48" was just over $10. I could have got a sheet 48" x 96" for $8 but I noticed they weren't quite flat. The bag of 6 looked totally flat and I've hot glued 3 together tonight so I should be able to get a 42-43" Nutball!
Yes, I know it is less forgiving than EPP but.....this particular Nutball is not going to be flown like my 20" Nutball is. I plan on strapping one, if not 2 point-and-shoot digicams on it for some nice, SLOW, airial photography.
Paint job, if any, will be very basic. Structural support and rigidity will be done with poly-strapping; a method I picked up from troynh here in the forums. Take a look at his build video for an explantion. The part that you want to watch starts around the 2:20 mark and ends around 5:20. For rudder strengthening I'm going to use bamboo skewers. I figure they should just drive right through this stuff. According to my non-scientific calculations I'm going to have about 32oz of thrust and about 22-25oz of plane, not including a camera.

Just to be clear, the following video is not mine, it is troynh's

Building the UFO-AP Part 1 (7 min 45 sec)

I've got pretty much everything I need here in the shop so the next couple days should be fun! Here's what I did today, not too much but hey, it was a lazy Sunday!