Advice please - MacBook screen sizes

Hi all,

I'm about to buy a new MacBook of some description, either refurbished or used. I have been on 13" 1280 x 800 up until now and I would like something with more work space for Reaper.

What are your thoughts on...

13" retina @ 2560 x 1600 px
vs
15" @ 1440 x 900 px
vs
15" @ 1680 x 1050 px?

Are higher pixel counts on smaller screen problematic for viewing (e.g. do things look too small)? Does reducing screen res in system prefs help or not?

I am not running big album projects with tons of tracks and plug-ins, and so far 4GB of RAM has worked fine for me on a 2007 Macbook. If I get, say, a 15" Macbook Pro, should I prioritize 8GB of RAM for performance over higher screen res to allow myself the option of bigger projects?

Any thoughts on Anti-glare vs Glossy?

Thanks so much!

Advice please - MacBook screen sizes