Well, you could get verified, mechs do appear on the classifieds sometimes. I would say, yes, there are some clone makers that get good reviews, and others that don't. Fasttech does have a message board where folks discuss the various clones and how they function (not just mods, but many clones they offer and etc.) It may be a good place to start if you are looking for a clone vs, authentic, which Fasttech also carries. Unless you are looking for something in particular, many single battery mod mechs aren't so expensive these days, so you may have more options than you think.
I am not the person to point you to one mech above others, but I am sure you'll get more specific feedback if you request it.
Good luck, and I hope you find something that works well for you.
Anna