I have my own 4x8 x 2" sheets of styrofoam.  Looking for a system that uses 4x8 sheets of styrofoam.  I saw a system years ago that used generic sheets of styrofoam.  If you know of an ICF system that holds the sheets together, has slots for rebar and is building code approved I am much obliged!

I just used 2" dow XPS with the new TF System studs. It work out very nice. I used my table saw to rip the panels down. This is a system I plan on using more often now that I had a chance to try it. If I use their EPS I will be real close to the local aluminum form guys by time they are done gluing on the foam. I the home owner wants to finish the basement I am a shoe in around here. Just for the record my local aluminum form guys are high in price which allows me to pull jobs off them in this economy, I guess they must have too much work! LOL.