Which plugins would I need?

Hi guys n gals

I am planning a build and wanting to use wordpress for it as I am not a programmer and the wordpress CMS looks like something I could handle with adding plugins etc.

If I get stuck I reckon I could always find someone to help withe some wordpress customisation or coding.

Ok, what i am after:

Lets say, for ease of discussion, I own a car wash. I dont and this business isnt about car washes but the examples fit nicely.

I want to sell car wash packages online.

On my wordpress site I have a shopping cart that will handle the sale of the car wash packages. People log on and buy one or 100, doesnt really matter. They get an account created for them (so I guess it is a membership type thing as well) and in this account it will show how many car washes they have bought.

There will also be a plugin in their portal that allows them to register a car and allot one of the car washes to it. They can register one car or 100 different cars (if they have a fleet etc).

The member would log into their portal, enter the registration number of the car into a form(?) and connect one of the car wash packages already bought and showing in their portal to the cars registration number.

It isnt possible just to send them out 100 vouchers for car washes so they can use them on whatever vehicle they like as the voucher has to be registered to the actual vehicle. Thats the way it works for me anyway.

I am wondering what sort of plugins would I need to be able to do this? Its ok if they need a bit of customising as I am sure I could find someone to do that.

Any help is appreciated.
Thanks