Shared or reseller hosting

I can't find a correct forum category, so I hope this a good location. My situation is nearly impossible to search on google, and is a little complicated to explain, but I am going to try my best. I am a web designer part-time, and aquired a new client. I am building approximately 100 websites for him. I purchased hosting on a shared platform.

The strange thing about this customer is that ALL of these websites will have the SAME EXACT content, just a different layout and different graphics. I hope I am allowed to post the website names, if not, I am sorry, and sure someone will delete this post or edited it, but I desperately need an accurate answer.... Here are 3 sample sites:

1. http://www.newyorkcityindustrialboilers.com/
2. http://www.industrialboilerservice.com/
3. http://www.industrialboilerhelp.com/

If you see each of those sites, same content.

Now for my question... I have been doing research, and found out that if I use one hosting package, and add-on domain names for each website, search engines will actually affect me negatively since a) all the content is the same b) they all use add-on domains c) its on shared hosting.

If I use a reseller hosting account, I don't use add-on domains. They will all still be on ONE hosting account, but each domain name has their own control panel. Will search engine be negative or a strike against me? All websites will still have the same exact content, but not with add-on domains.

This is extremely important to me, I hope someone can help. If not help, maybe let me know where to ask this question.

Thanks guys!

You could be sneaky and just go with a single hosting package and then redirect each domain name to ther own custom home page based on the url used. Google shouldn't penalise you, as to them, they are different sites.

You'll want to do a .htaccess redirect. (http://www.javascriptkit.com/howto/htaccess7.shtml)

Also I don't recommend the whole "shared hosting" scene of web hosts, alot of them are quite slow and oversell.
I personally use mediatemple.net, it's a bit pricey, however you get what you pay for. Any specific reason he is going to
have 100 websites?

Google should penalise you for having the same content whether you're on the same server or different ones. Identical content doesn't benefit visitors, hence it incurs a penalty. Getting a Reseller account won't necessarily give you more IPs, and if it does then you're unlikely to find anyone who'll sell you 100 IPs at a reasonable price, if at all. Even if you could get them, it won't necessarily benefit you.

As for "it is an addon domain" - AFAIK there is absolutely NO WAY you can tell that (other than by breaking the config). None of the standard HTTP headers are an addon domain flag. In fact, I think it is basically just a cPanel terminology thing.

I'd say just get a shared account (or have your own Reseller/VPS and put all the customers on their own chunk) and help the web by just pointing all the websites to a single domain using redirects. It covers the typos for the customer, it stops you being penalised for duplicate content, and it stops the company losing customers when people get annoyed that half of the sites they click on are the SAME DAMNED THING! We don't need more duplicated junk on the web.