We are a bootstrapped web start up. We have a LAMP web application that we expect relatively low to mid traffic because users need an account to log in. Our current approach is to colocate two servers, a web and mysql database server. We are planning to use Ubuntu Server 9.04.

We have shopped around for dedicated servers but the price range from $900 to $1500 per month, therefore we are exploring the colocation approach. We are considering purchasing two Mac Minis (2.0GHz Intel Core 2 Duo 2 Gb RAM) because we are familiar with the machines are the prices are relatively inexpensive.

What are the pros and cons of using these 'non-server' grade machines? We would install Ubuntu Sever and attach firewire external hard drives.

Any advice on how to set up 'good-and-economic' web/database servers is welcomed.