From my limited experience with TWA and Southwest group desks, they won't offer you anything cheaper-- and Southwest is less likely to offer you $88x45 than TWA. It seems Southwest looks at their different fares and averages things out, i.e. 10 tix at $88 plus 10 tix at $120 plus 10 tix at $150..... A bonus, though, is SW will allow free name changes until close to departure, and both airlines should give you 1 free ticket with 40 passengers.... the Southwest ticket may be free to anywhere they go.

But a chartered bus would be a lot cheaper.... And no fee for parking at the airport.