Hostgator reseller hosting. Best for SEO??

This advice is probably a little past due, considering that your original post was back in mid-May, but I'll give you my two cents anyway since nobody else did. You only need to host your sites on different IPs if you plan on creating some sort of link network, since you don't want Google to see that one unique IP is linking to several other sites on that same exact IP - that may be a little shady in their eyes. So if you are planning on building some sort of link network, like a high PR link network, host them on separate IPs, with WhoIs protection, no Google Analytics/Webmaster Tools/AdSense, don't link them to each other, and basically don't do anything else that Google can use to trace a site back to you as owner.

As for having all of your money sites on the same IP (i.e. via shared hosting), you should be fine. When you use shared hosting, the term "shared" doesn't come from the fact that all of your websites are shared on the same IP; rather, it comes from the fact that you are sharing that IP with thousands (and I mean thousands) of other people on the same hosting plan/grid/etc. as you. And Google understands this. I have about 80 money sites all in the same shared hosting account, and everything's been fine. Hope that helps.

It is only natural that if you are an authority in some niche that you will have multiple websites that you link together eg. a static website and a blog. Google isn't going to penalise you for this.

Reseller hosting is important if you have plenty of websites and want to keep the page speed high. Then it is easy to control the different packages from one interface. Reseller packages have more resources so to speak. If you have five or ten little blogs it is not really neccessary.