Dean
As a web development company, I have experienced an unrealistic amount of hosting companies. I have also been very closely involved in researching cloud hosting solutions for sites in LAMP and Windows stacks.
You specified GoDaddy, 1And1, and Mochahost for sites with Linux micro-sizes, so I assume that you use a benchmark of between 2 and 4 dollars per month for the site. It looks like you have "several" sites (5ish?) And you need at least one database.
I have yet to see some tool that will move more than the simplest ones (i.e. files, not db) to cloud hosting. Like most people, you cannot do this to avoid the initial setup of your environment. (You should also consider your time. If you spend 10 hours on this, you can bill customers 10 x $ per hour and just bought a hosting service for your friends and family.)
When you look at AWS (or anyone), remember these things:
Calculate cycles only where it starts. When you buy hosting from traditional Internet service providers, they sell you cycles, disk space and database hosting. Their default levels for allowed cycles, database size, and traffic are also usually much higher before you stop or charge for "excessive" or excessive use.
The cost factor of your 1 database and consider how likely you need more. Database hosting fees can significantly increase the cost of the clouds.
While you probably need a few CC (computational cycles) for your main sites, the maximum level of free host is still pretty low. Predict a breakthrough through free hosting and be charged monthly.
Disk space is also exposed. Factor of your costs for CC, DB and HDD using their price assessment: http://calculator.s3.amazonaws.com/calc5.html
If your friends and relatives want to have access to the system, they will not receive it unless you use a hosting company that allows "white marking" and provides the opportunity to split the main account into a smaller mini-hosting Account. They can even tune in to allow self-administration and direct billing if you go with a host like www.rackspace.com. The problem is that you donβt look like you want to bill someone and their minimum account is probably too big for your needs.
Remember that GoDaddy (and others) often give away a year of hosting, even with simple domain registration. Before I got my own servers, I used the BIG advantage of these. I probably got as 40+ free hosting accounts, etc. In my life as a client. (I still register tons of domain through them. I also resell their hosting.)
If you have not already done so, consider using CMS systems that support portaling (one instance, many websites in different domains). Although I personally prefer DotNetNuke, I'm sure one of its competitors in the LAMP stack can do the same for you. This will allow you to use only one database and simplify your needs.
Hope this helps you make a well-educated choice. I think it will be a fine line between the benefits and costs. Only knowledge of the exact size of each site, each database and typical traffic will allow this to be determined in advance. The number of databases and traffic will be your main "enemies." Optimize files to reduce disk requirements and your traffic levels in terms of transferred data.
Good luck.