A couple of faily dumb monitor (display) questions

[Spikey Horse]

I am thinking of what new display set up I should get. I am currently using 17" CRT! But I also have a 15" TFT I use for live with my old G4.

I am probably going to go for

2x 17" TFT

or

1x 19" TFT

Anyway my question is can you mix different sizes of monitors? Because if I get just the 19" (DVI) I might like to occasionally add the 17" CRT when mixing or perhaps the 15" which is also analog. It's just I've never seen different sized displays used together.

Also when I was looking at 19" displays I noticed some differences in the aspect ratio of different models ... IOW some were quite square, some were more widescreen. I was quite taken with the widescreeen ones because it suits audio editing more. Any comments on using those, or any suggestions for good models (19") I could look out for (I'm in the UK)

Thanks!