Narrowing Down Your Niche vs. Finding Suppliers

So which comes first: narrowing down the niche idea or finding suppliers? This is a question that is coming to my attention more and more as I teach others how to build their own internet businesses.

Narrowing down the niche:

• You want to have high demand (see www.digitalpoint.com/tools/suggestion) - at least 16 searches per day to make the idea even worth your time
• You want to have minimal competition (use google and type in allintitle:"any keyword phrase" to see what the real competition is for Search Engine Placement - my target numbers are 30,000 competitors or less; this usually means that within 2-4 months I may be close to the front page of Google if I'm aggressive with other marketing strategies
• As your narrowing down the niche, you don't want to get "over excited" because the other speed bump you may run in to is....Finding Suppliers

Keyword Phrase-----digitalpoint.com/tools/suggestion-----allintitle:"keyword pharse"
-----------------------------target: 16/day+ ----------------target: less than 30,000

clogging -----------------137.0/day ------------------------------37,100
clogging shoes -----------68.0/day -------------------------------730
clogging cue sheets ------23.0/day -------------------------------285

Finding Suppliers - Why not look for these first?

• There are many ways to find suppliers: contact them directly, talk to competitors, use tools like TheShipper

As I think about it, why not look for suppliers first and then, when suppliers are found, think about keywords and phrases you can optimize with? To me, this seems much easier and a better way to manage time.

What are your thoughts?