What would you cross on this stud we have the following mares and a Dodadash filly 

SPEED

1st mare and Doodadash filly should make nice babies with that stud. Don't know about the FG mare with the FG stud. That might be a hard headed project horse. 

I've seen First Down Jewel mares cross good on multiple sires. Personally, just on pedigree....I like to acutally see the mare before deciding, I'd go with another running bred sire. A First Down Jewel daughter with Game Patriot produced Jet Black Patriot. That's just one example.