Does anyone out there have a preference as to which hardwood manufacturers they prefer in terms of the quality of the product? Browsing the web I've seen many on line suppliers offering products from a wide range of manufacturers. Are there certain companies that stand out, good or bad? I currently work for a flooring sub contractor but ultimately would like to go out on my own. My plan would be to offer my clients a start to finish approach of purchasing the wood, trim, transitions, etc, and installing it with the client's only effort being selecting what type and colour of wood they would like. I'd like to find a supplier who offers a superior product and stick with them. Is it a matter of trial and error? Will I have to jump from manufacturer to manufacturer until I find acceptable quality?

You're probably better off selecting a good local flooring distributor, if you are talking about UNFINISHED flooring. Over the years, there's been some brands that have been consistent. But a problem is that what you want and are used to may not be available sometimes. Don't get too hung up on certain brands. Instead, offer "grades" according to NOFMA. From best to worst they are:
* Clear
* Select and Better
* Select
* #1 Common
* #2 Common

Then there are specified characteristics and the type of cut, such as shorts or quarter sawn. These refers only to red and white oak. Maple is graded differently and there aren't really any grading rules for imports apart from what the individual manufacturer determines it to be. If you go with a good distributor, they can supply you with samples and educate you on what they can offer. Learn as much as you can about wood, wood flooring, grading, milling, styles, types of woods and floors, etc. Then you'll be better prepared to help your customers.