Multiple domains, one installation

Hi,

A client of mine has an Irish e-commerce site. He is going to expand his business to the UK and wants to run the site on a UK domain too.

He wants to have the same products/categories/pages/theme/settings as on the Irish site. The difference is going to be in prices (currency), some pages (like About Us), site title, description, contact information.

So I am looking for a robust solution which allows to change the content depending on the current domain.

We considered the following possible solutions:

• A multisite solution using ThreeWP broadcast plugin — It is not exactly the right fit because the WP and theme’s settings will be independent. And the network directly is not recommended for the sites that are going to share data.
• An import/export solution. It is supposed to make a scheduled export from the Irish site with the WP all import plugin, then change the data in the exported file (prices) with a server-side script, then make a scheduled import to the UK site — This requires using non-WP tool and doesn’t seem robust at all. I am sure, this is a headache
• A single installation solution. Point both domains to the same folder and use a plugin which allows to change content conditionally depending on the current domain

The latter seems simpler and more robust than others and I started to look for a plugin which can handle this. I found a couple, but they have not been updated for years and does not seem to be working.

Have you built such a system? Is there something you can recommend for it?

The second part (“do not do it”):
As far as I understand, after doing so (two domains with mostly the same content), the UK domain, as the later one, will be dead for Google and other search engines, is that correct? Is there a way to prevent this?