What paint should I use

A white screen would do ,but if you want to add light in the room on some days you might want to go with a gray screen. you don't need a dark gray screen.

Have you projected onto the Kilz2 yet?

Do you have a brand preference for paint?

Before you do anything wait until the projector comes in and you have watched a few things with it.

If you decide to stick with a white screen, you may want to repaint with something a little more durable. I would recommend you consider the Behr Exterior Premium Plus ULTRA Flat UPW #4850. It rolls well and levels out very well. It is also a very bright white. This is an exterior paint that will be more durable and washable once it has cured.

If you are going to go gray then you could go with the Sherwin Williams Duration base tinted with one of the following:

>>> 199 203 203 - SW 7071 GRAY SCREEN

N8 == 202 202 202

>>> 204 205 202 - SW 7064 PASSIVE *

N8.5 == 215 215 215

>>> 215 218 218 - SW 6253 OLYMPUS WHITE
>>> 221 223 220 - SW 7070 SITE WHITE

>>> 224 224 223 - SW 6259 SPATIAL WHITE *
>>> 227 227 229 - SW 6539 SOOTHING WHITE *

N9 == 229 229 229
Click tints to view color visualization.
* Tints that appear the most neutral to me. The "Passive" looks like a very good darker gray close to N8, while the "Spatial White" or "Soothing White" look like very good lighter grays approaching an N9. Given your darker room colors and light control I would suggest you err on the lighter side. So I would be inclined towards the "Soothing White".

BUT first try the Kilz2 alone and also consider making up a sample panel of the "Soothing White" to try before painting the whole screen.

If it's too white, you can always turn down the contrast for less peak white level. What the gray paints do is bring down the perceived black level. With the latest PJs, you can give up peak light output for better gray-scale and shadow detail.

what type of player are you using? i.e blu-ray ,hd-dvd ,sd-dvd

batman for blacks
5th. element for flesh tones
cars for color

just to name a few

A superb light gray is True Value Winter Mist on top of Kilz2 coats.

Sorry, no.
It is a fantastic, cheap diy screen though.

The Sherwin Williams colors are not really mine so to speak. All the near neutral gray tints were determined from the EasyRGB website. I did go through a few brands and sift out the most neutral looking tints. These are summarized in the Beginner's Guide and there are some visualizations to give some idea of how close to neutral the tints are. Another source of inexpensive near neutral gray paint is the Glidden (CIL/DULUX) tints shown here.