Advertising Scamps for new maketing campaigns

We are looking for marketing/advertising input to design advertising scamps that will be used in several different campaigns. Initially we will work together on one campaign to develop scamps - that is the creative concept and copy headline. These do not need to be worked up as Mac artwork (we have designers who can do that).

Want to work quickly on first campaign and generate scamps/ideas. Need to understand how briefing process will work in context of PPH. We are in N. London and can meet face-to-face for briefing in London area.

There are several campaigns in the pipeline, so we want to build a relationship and find a creative talent that is on our wavelength. Not clear how this work is best priced, but we prefer fixed price to keep costs manageable. Can give examples of the kind of thing we are looking for, but any experienced ad person will already know.