I have 4 sites on the same ip built around a very narrow niche that's hard to get backlinks for. The 4 sites are interlinked through a script so the links are something like this:

http://domain1.com/cgi-bin/link.cgi?...://domain2.com

I'm getting rid of the script and just going to interlink them with normal links instead of through the script (don't know if that makes a difference if they're currently interlinked through a script so I mentioned it). I'm changing the sites over to WP blogs using content that is spun for each site and posted in different order. So each post on each site will have a unique version but they are all based on the same original content.

1. Since right now these are all on the same ip will I see any SEO benefit by interlinking them if I move them to different ips since google knows they were originally on the same ip?

2. I can get additional ips through my host but they can't guarantee different c-class ips. Is that sufficient or should I move to a host that offers different c-class ips?

3. I'm going to add three new WP blogs like those above and link them with the current four. Should I leave my current four on the same ip and just put the new three on different ips?

I appreciate any advice...