Comment Forget LAMP, use GAE, 'servers' are so 2 years ago (Score 1) 456
Convert your site to python/big table and use Google App Engine. Great up time, free (besides dev time) to get started and cheap to scale. You could do java also but I like python much better.
PS: Of course there will be people who will tell you GAE is a bad idea, every solution has negatives, you never will find a perfect one. It is better to know the weaknesses than be surprised later. I've done site with LAMP and GAE, I like GAE better. The best thing about it is you spend a much higher percentage of you time on your web app code and less on hosting, provisioning, load projections, deployment, scaling issues, server config, extension updating, etc.