use DVI to connect your PC, and HDMI to connect you PS3. I doubt your going to find two HDMI on a monitor as DVI is preferable. that's TV territory. or you could use an HDMI switch.
Actually I have found a monitor with my specs for $170 but it didn't have a speaker. It did have 2 hdmi though, also using my graphics card without using an HDMI cable would kind of be a waste.