Work for Contractor or Company?

Company. They are more likely to Employ Admins.

I'd keep my current job till I found one though... admin jobs are scarce these days.

Always look to be an internal employee, not an external contractor, so that when it comes to benefits, pay, and environment you're usually a little more stable than as a contractor.

As my former employer (contractor of sorts) lost business, the need for a local LAN admin was diminished and I was let go because of it. I am now with a major accounting firm as an internal admin and feel much more confortable compared to being worried about contracts being won and lost...

One thing to consider is that in a contractor kind of a company there is usually a faster pace for learning curves to progress since there's more competition. It may depend on where you are in your career, not certifications, to determine what is best for you. Only youcan weigh these options though.