[Delivos]

Loading in frames is an old spammer trick and really breaks the URL bar, I'd say avoid it like the plague - though if you're building MFA then help yourself!

You should be fine for a while, until the engines catch on that content has changed. What's on the established site at the moment? It may well be the case that good incoming links are the power behind your high rankings, and those links will carry on after you redirect the site.