I'm looking to purchase a multi-domain SSL Certificate but am not sure if there's anything special I should be looking for. It will be running off an IIS 7.5 web server and used for different blogs, webmail etc. There's not going to be any commercial activity on it so I just need something to make it secure for people logging in.

I'm not doing my own as the general public will be logging into some sites and I don't want them to have to worry about certifcate pop-ups.

I'm looking to have about 10 domains to start using them.

This is on a Rackspace cloud server so I would prefer to do them all of of one IP as there's only a max of 4 per server.

Is there any major differences between the following?

Right now GoDaddy seems the best as I don't need anything special and they have good prices 10 domains for $170/yr http://www.godaddy.com/ssl/ssl-certificates.aspx?isc=sslqgca02a&ci=9039

StartSSL looks like it has multiple domain names for $49 and I'd imagine $49 for each additional domain? They look to be for 2 years though: https://www.startssl.com/?app=39

Comodo seems ok, but you only get 3 domains for $330 and then each additional one costs $95! http://www.comodo.com/business-security/digital-certificates/multi-domain-ssl.php

Geocerts have 10 for $549, but they're aimed at business: http://www.geocerts.com/ssl/tbidmd

GlobeSSL has one for $155 but again, that's 3 domains. Though it's only $50 USD for an additional year. https://www.globessl.com/SSL-Certificates,Globe-Multi-Domain-SSL.htm#