http://johnmayer.yuku.com...&advanced=1#.UER9Y9ZlQ3g

There are 6 pages of results with Blues Jr in the title, this question has been discussed to death!

Anyway,
1. Yeah you kindof can, but it's 50% how you play the note, 50% a TR.
2. There's no way to know, which you prefer. Go and try them! Just go to your local music store and try as many small F -style amps as possible you might find something completely random that you love. Which city are you studying in?