4 Tables to 8 Tables ... Am I ready?

Hey guys. I have been playing poker for a pretty decent amount of time now and feel that I have been doing alright. I make a mistake now and then, but I am working on fixing them. Anyways, I have been 4 tabling party and skins since summertime and have been fairly sucessful (except until recently when I tilted and and decided to sit down at the 10/20 and blow my bankroll in one hand).
Anyways I have been 4 tabling the 25NL again and been grinding it quite well.

I am thinknig of moving to 8 tables over the break when I am back home and have my desktop and I would like some advice.

First of all, do you people who 8 table do it at the NL cashgames more, SNG, or here, at the (SS)NL cashgames?
What is more profitable and easiest?

Also, do you do it with one or two monitors? I have heard of people doing 9 tables I believe on the party poker with a special monitor.

When doing 8 tables, doe sit get really hectic? Do you tend to tighten up even more so you can focus more on the big hands?

Any advice would be great.

Thanks