Can anyone help me in what wonders to help a city towards producing Great Merchants. I get maybe 2 a game. But I would like to produce more since I love to use the on trade missions.

I think you're asking the wrong question!

The best way to get lots of great merchants is to have a city with lots of merchant specialists. If you can build the national epic there, even better.

While, say, getting the great lighthouse and colossus in the same city is nice for producing great merchants, they simply don't compare to the power of the specialists. (Of course, if you can get a city with those wonders, and lots of merchant specialists, and the national epic... :eek:)