I don't know about dalites acoustically transparant screens, Stewart is the king in acoustic screens as far as I know. Be aware there is a current issue with the Sony vw10HT and stewert microperf screens where you get a moire distortion.
As far as good dalite screens, a popular choice (for the sony 10ht) is the HiPower material. There are several users at www.thebigpicturedvd.com
Sony 10HT forum that swear by them. I myself ordered one but won't receive it in two weeks! (argh the agony)
Good luck! Excellent choice of projector!
It's great to have all this great gear. But I'd instead put all that money into software (Movies) I'd have SOMETHING TO WATCH ON ALL THIS GREAT GEAR. Doh!