I'm hoping to be able to afford a couple of suppressors in the near future.

With all the makes and models, is there one better than another?

I'd be interested in; .22lr, .223, 9mm, .30 rifle, .45

The only thing i've come up with is that the manufacterers have no set way of measuring DB reduction, so i can't trust their claims.

I'm looking at;
reliability/quality
performance
ease of use/maintenance
cost

There are differances between non f/a and f/a rated, what are they?

I'll be going the corp route.