I used to have a pulldown screen in my last setup. I had bought it originally because of budget and because my boys were much younger at the time and I was worried about them using it as a colouring board. I never ended up retracting it though (which is a pain anyway) so at this point, I would...
:)
Depends on the budget. A Stewart Luxus Deluxe Firehawk would be ideal for it. It will increase your projector's black level, colour contrast/saturation and reduce problems with ambient light.
Stewart Firehawk info