There are a lot of cool tools for making powerful \"single-page\" JavaScript websites nowadays. In my opinion, this is done right by letting the server act as an API (and no
To take a slightly different angle, your second solution would be the correct one in terms of accessibility...you would be providing alternative content to users who cannot use javascript (those with screen readers, etc.).
This would automatically add the benefits of SEO and, in my opinion, would not be seen as a 'naughty' technique by Google.