Id rather have a good working bitch than good working dog if I had to start from scratch, having been to quite a few lads kennels over the years I'd say working dogs outweigh working bitches maybe 3 or 4 to 1.
After taking the young dog out last week to check a few empty earths (purposely) I dug him today at 3ft, he worked his game well, dug him in a stop end locked, his first 2 digs I dug him locked on in the tube.
Read this earlier but signal was bad I was going to say it could be lack of calcium, get to chemist or pets 4 homes and get calcium tablets but make sure you give them right amount, defo get sum before they whelp just in case.