I had a similar projector when I was starting out, and ended up with a Dalite Hipower screen (floor mount only). It was the only one that would give enough gain. Homemade screens just aren't bright enough. Also max size is probabaly 60x80 (100" diagonal 4:3 format). This will give you just enough lumens to get by. Cost is around $300 or less. I think AVS carries them, also cousinsvideo.com. If you must do a ceiling mount, then look for a Draper M2500 which is a little more expensive but has similar gain characteristics to the HiPower, but is reflective--light reflects on an equal angle (the HiPower is retroreflective--light reflects back to source). If you go homemade, then I wouldn't try for anything bigger than a 6 foot diagonal as you will overdrive the projector.
As a quick fix, get the biggest and whitest window shade you can find from Home Depot, or similar, and try this.