Unless you can make it look natural, you probably should not have more than a couple of links from the same web 2.0 to the same website in a systematic way. This is a major footprint.
You wanna build links? Build links then. Stop calculating and go out and do whatever you wanna do. There's no safe way to do SEO out there.
I usually build 5k+ links to each web 2.0s.
May want to link out to different authority sites too, just linking to your money site (and the same IP) all the time leaves a footprint.