I think the general term for this is “domain sniping” or “catching”. From this, I also found this paid service, catches.io; can’t tell if it or dropcatch is better. They both only charge you when they are successful in catching the domain for you, which is good.

In general, I second the notion that one probably can’t get around paying for a professional, paid service, since one is up against professionalized scoopers (godaddy and the like), who have put a lot of optimization (down to the placing of their servers) into trying to get an edge over legitimate buyers and competing scoopers.