[Mark Laslo] "I have already learned that progressive seems to be the way to go. What is the file size of 1080/30p (since the AG-HMC150 doesn't support 60p, does anything?)"
Who told you this? Progressive for 720 ONLY. If you want to shoot 1080, you want to work with 1080/60i.
There are a few apps (iphone) that will calculate your file sizes.
http://www.aja.com/products/software/
Steve Eisen
Eisen Video Productions
Vice President
Chicago Final Cut Pro Users Group