Might I suggest setting aside the time to learn ITA Matrix. It accesses the GDS system directly and has the flexibility to let you build exactly what you want, if it exists at all. It then spits out the ticketing code sequence that you can give to any travel agent for them to process the ticket for you. It's great for forcing certain city pairs, carriers, and classes, and varying all those withina ticket in terms of timing and class. Very useful and powerful tool that Google do almost nothing to let people know it exists.