Domain Aliasing and search engine rankings

[Voda123]

Hi

I am setting up a website that will cover 32 counties in Ireland. So it's not a national website but 32 county websites. The choice is this:

I use ASP & MS Sql - I can have one database, one primary domain name and 31 domain aliases pointing to the primary. (with count name interchangeable)

Or I could use PHP and have one database and 32 individually hosted websites

Which option would be better foe search rankings?

Thanks