I host ~25 low traffic websites & have some questions about moving to AWS

I've been using shared hosting, dedicated servers & dedicated virtual servers with pretty straight forward pricing for years now, but after just hating the service, UI & reliability most of the services i've come across (godaddy, 1&1, network solutions, dreamhost, etc) and then recently running into an issue with MediaTemple not allowing adult sites (i host 2 adult sites)... AWS seems to be my final frontier of hosting.

So, since I want to put all my sites on 1 server (they're mostly side projects & a few clients sites) to make my life easier... What does HN suggest when using AWS?

~20 of the sites average 10-50 hits a day

~5 of the sites average 100-300 hits a day

About once a month, when mentioned by a blog or new marketing comes out, 2 or 3 of the sites will hit 1000 hits a day for a day or two and then go back down to their regular traffic sizes.

~5 are Magento stores

~15 are WordPress sites

~5 are static html sites with just a few pages

All but 1 of the Magento stores are actually just Magento sites being worked on, and wont live on the server for more than few months time. However there will always be at least this many on the box as i work on more stores.

My questions:

1. What service is right for me? EC2?

2. Is AWS just total overkill?

3. If AWS is a good idea, what size instance/server/service should i use?

4. What kind of prices am I looking at?

I would love to pay no more than 100/month if at all possible, but obviously if I need to I'm open to paying more. I am a firm believer in you get what you pay for. If better hosting costs more, than so be it.