There are off-web considerations also, particularly if you choose to go for multiple domains.
There's the obvious one of the cost of running multiple link-building campaigns.
Then there's the question of what to do with printed materials. Are brochures/leaflets etc to be reprinted for each target market with the localised url? Or is there to be one main url with a country choice page? Which leads on to...
Another issue is what to do if you get one countries' customers on another countries' site (eg a UK visitor on say a US site). Do you redirect them? Or just hope they will notice the country links?
My experience is that there are loads of problematic ramifications. There's a lot of worry about whether to go for domains or subdomains or directories. But it's what happens afterwards that I have found really difficult.
That isn't much of an answer. But it is a warning that the best solution for seo can be quite hard to manage.
