2 websites, same IP, selling same products. Will this be an SEO issue?

[The Cricketer]

I am using Cpanel with my shared host at the moment. I currently have 2 websites with my host, 1 on one shared server and one on the other, both websites having a different IP address.

These two websites will sell, for argument's sake, the same products as each other. To avoid data duplication and to save time I want both websites to use the same database to display the products.

In the current situation I am told that it's not best practice to access a database from server to server due to speed etc.

So my hosting company has advised that I use an add on domain on one of the accounts so that both websites are on the same account - same ip.

What I want to know is, from any SEO gurus out there, will putting two websites on the same ip have severe ramifications? i.e. both websites will be displaying the same products, so will the search engines only display one of the website versions? and will the SEs view the 2 websites as websites in their own right? even though one website is effectively a folder within the other website.

Any views will be appreciated.