Nick,
Did you at any point consider a DIY screen? I don't know how well respected the reviews are at ProjectorCentral, but this review mentions that they felt the Goo Systems Digital Grey Lite paint "clearly" outperformed the Carada High Contrast Gray screen. I'm a bit skeptical of such a claim, but here it is:
http://www.projectorcentral.com/goo_...or_screens.htm
chuck