Best car seat and what type?

Wen
So this question will be a bit longer but I hope you all can help me.
1. What is the best way to research car seats and ratings? Any websites? Your recommended brands?
2. I have been debating the following: I like the idea of a convertible car seat that lasts for a few years but it seems they are all without a handle to carry them and are stuck in the car but being able to take them out seems to be very convenient in those first months. Should I just get a "cheap" infant car seat and then a nicer convertible one or what would you recommend?
I'm sorry, I know this question was long but I could really use your help!