1) We are deploying a SAAS that needs a near 100% uptime since customers will be connecting to our server every minute. 2) We need a Mysql db and a php environment. 3) To keep our costs down initially (before we truly scale), what would a good server architecture be for us? 4) Would a PAAS be a good option? Or should we go for 2 dedicated servers with load balancing? Since we want to keep our costs down initially (bootstrapped!), we don't want to hire a "network engineer"... At least not until our service hits a certain benchmark. So any advice would be welcome... Thanks in advance.
Take a look at Google Compute Engine. You'll pay by the drink, metered on your resource usage. Infrastructure cost drop drastically and you'll be on "GOOGLE's" gear / cloud. As an example, take a look at GetCloudCenter.com - the portal is running on GCE using LAMp servers, PHP, not sure about the DB side of things. They offer a demo portal to spin up and sell DaaS. Best of luck!