Can anyone advise me on how I can go about finding out who the top rated manufacturers are for variable frequency drives.......I'm sure the names and numbers are out there somewhere, but so far I have yet to locate them......Thank You.

The problem with that is the term "top rated".

Rated by whom? There is no international "rating agency" that I am aware of and if there were, there is so much money in that game that I would be highly suspicious of bias. I have seen several attempts at getting user input in forums like this, but it always quickly degenerates into a series of blatant sales pitches by manufacturers or their agents, rendering them useless. I work for one of the manufacturers, I will tell you that we make THE BEST VFD out there and ALL OTHERS ARE JUNK. But I would be disingenuous if I were to do that...

My advice:

• Talk to your LOCAL suppliers. VFDs are NOT something you want to buy over the internet unless you want to be your own tech support system. Ask around to other users in your area as to who they have had success with and who blows them off when they have issues.
  
• Look for those tho are COMMITTED to providing service for the long haul, meaning they maintain a trained staff including applications engineers and technicians. Anybody can rely upon a manufacturer to send someone out on a plane, but that does little good when you are hemorrhaging money while your process is shut down.
  
• Look only at manufacturers who have 24hr service support available. Then get the phone number and call it to see how long it takes to get help. One well known internet supplier advertises a toll free call in 24hr tech support line, but I called it once just to see and was left on hold for 6 hours!
  
• Only buy as much technology and features as you intend to use right now and maybe 2 years into the future if you know that. Any further and the cost of future technology will have dropped enough by then that you will likely change it out anyway. besides that, the product life cycle of VFDs is down to 5 years or less for manufacturers, so you are looking at maybe a maximum of 12 years of serviceable life, if even that. So since most VFDs now have most features, the manufacturer is not as important as it used to be. Most are made in automated facilities and with manufacturer's margins being so low now, those with poor quality are usually quickly driven out of the business by the cost of support, or their reputations precede them and everyone but the bottom feeders stay clear. Besides, may of the "popular" brands are now brand labeled and intermingled with each other so much that you may be paying extra just for brand names to get the same thing you could have bought from a different trusted source.

Bottom line, trust your own local resources and those who commit to supporting YOU, not the marketing spin and price choppers.
Good luck.