Can anyone help me find a cell phone and plan?

I have been out of the country for four years. I live in Washington State. I know the tax on cell phone plans here is about 20%.

Here are what I must have:
At least 300 minutes
Texting, Email capabilities really cheap/unlimited

Here’s what I’d like:
Instant messaging
Maybe skype
Unlimited mobile to mobile (like Sprint)

The icing:
GPS
Unlimited Data for the web

What are some ways I can fill what I must have? (phones/plans)
I know how expensive and good the best stuff is, but how about the middle of the pack?

How about for things I would like?

I’m also worried about reliability of the providers. Is there a big difference between AT&T, Verizon, and Sprint?
How about the smaller providers Boostmobile, T-mobile, Virgin etc…

Take for example Virgin mobile prepaid. $25 a month Unlimited Text, Email, Data and Web plus 300 minutes.
I find this very suspect. It seems too good for such a low cost.

One major reason I want to be able to connect to the web is I have friends in Japan. I would like to be able to IM or email them, but I’m not sure how much that really costs to do.

I also thought it would be cheaper to use skype and call them internationally.

If you have any other thoughts please feel free to tell me.