2 size 940x198 (but would look good in smaller size width)
Large Banner 1 - 1 size 940x198 should be about creating products, like software, iphone apps, etc.
Large Banner 2 - 1 size 940x198 should be about auctions (see attached picture to incorporate), incorporate images of real estate, pottery, vases, toys, wooden antiques... ***For this one I like the picture of the woman on the left. So if you can create a sexy businesswoman image like this, with lady on the phone -- it would be great.
2 smaller sizes
Banner 1 -(see 1 banner on [url removed, login to view] on left side) create another banner in the same size promoting graphics packages
Banner 2 - create second banner size 125x125 regarding headline software that is advertised there already