Questions about PSP

Good day, ladies and gentlemen.
Began I often ride in the trip, so decided to buy a portable console in the way to run, as a person who grew up in the 90s, I wanted that type of thread wore/blew/Sega, because to read 10-12 hours in a row really tired.
I thought I'll come on a thread of the market - and there are mountains of all sorts of different portative.
Yeah, right... well, there's nothing but a couple of not particularly outstanding CityCat no(abydno) In this regard, I decided to look in the direction of the outdated classics, like the PSP. But since my experience portable gaming not gone beyond the electronics, then immediately raised a number of issues:
1. How do you feel emulators of old consoles on a PSP? is it comfortable at all to play?
2. What should be the firmware, so there was no hassle then with the software,in Google different writing?
3. On which model to follow? In my city only sell 100x.
4. How long does the battery and that magic memory card needs to be( there's some technology has to be supported)
Thank you all for your attention.