Need a plugin suggestion

Ok, so I am wanting to add a feature to my site and just need a good plugin/place to start. I have a pen-pal site for inmates, most federal inmates have email access but most state inmates do not. I want to allow people to write an email to state inmates and I will forward it to them as snail mail and charge $1 (just a convenience feature to give the state guys a better chance for results in this digital world). I know that I can create a form and integrate it with paypal and that would sort of serve the purpose for a one time user but I want to actually allow people to be able to create an account, add funds, have an address book, be able to upload photos etc, oh and be able configure and deduct from account funds.. Any good suggestions on where I should start with this would be greatly appreciated… emailingaprisoner.com is an example very similar to what I am trying to do… Thanks