Whenever I do texture, I add paint to the mud to give it the ability to be painted over with latex material without being disolved by the first coat of latex, which would need to be a primer.
Understand that if you do this, the texture will be permanent!
I'd start by exprirementing on a piece of drywall or plywood. Start with a small quanitity ofpaint and mud, don't mix up a whole batch until your ready. Using a small bucket, mix your material at a ratio of 1 to 1, then see if it gives you the effect your after. Ater you've established your ratio, then mix what you need to do the whole project. Texture paints will only cover about 150-200 SqFt per gallon, but err on the generous side because remixing a second amount may slighly change the effect you get. Paints that have been mixed with joint compound will only last in the can for a week or so, then they go bad, and you really don't want to smell it after that.
Prime your walls with a wallcovering primer. I highly recomend "UltraPrime 977" marketed by Roman Adhesives, it's an excellent product and will allow the best adhesion of the material. This will seal the wall well enough to slow the dry time of your material, giving you ample time to get the effect your after.
As Steve told you, you will need to paint this when your done. Paint with compound added to it is way to porous to serve as a finish. Without a finish paint, it will be filthy in less than a year. Wait a sufficient amount of time to allow the texture to fully dry before you paint it, about 2 days, more if it's humid. Then use a GOOD QUALITY latex primer. I highly recomend Benjamin Moore products. Moore's "First Coat" primer is easy to use and has excellent for you purpose.