New Owner--backup camera and nav addon

Hello fellow Prius Modifiers!

I want to pimp my Prius. I have a Prius II--but I want to add the GPS and backup camera. I really need your help. I don't know who to trust. Stores and the dealership all give me different plans and prices. I don't have a lot of money--I have been saving for this upgrade! I think when sellers see me they think $$$ because I'm a "young girl" who doesn't understand this car stuff fully...

Here are my questions:

1. Should I buy the backup camera and Navigation through the dealership, and have a installation store install it to save more?
--How much does the dealer charge for the parts?
--How much should the installation run?
--Can I order dealer parts from China/Japan to save money? My dealership is so expensive for andthing and everything.

2) Did you buy non-dealer parts? If so...
--What GPS model did you buy? Where did you mount it on your Prius?
--What backup camera model did you buy?
--How much did they run you?
--Were you able to buy a 2-in-1?

3) I am open to getting an in-dash set-up or a portable mounted device. But I don't really want a ton of stuff and wires cluttering the interior. What has been your experience?

I really love my Prius.
56 MPG so far!

Thank you in advance for any advice you can offer,

Hirus
The Happy Prius Owner