60" spade will work "ok", 90" better.    Ive had way better luck moving trees when the ground is moist, so survival should be good.     Im around 90% survival rate over the last 13 years of moving trees.   Of those 10% that died, I'd say 90%  were from not watering properly.   Keep em moist for a year, especially going into freeze and through the heat of summer.   Staking them for year helps.

 If you do allot of trees, setup a water line that will water to them all at the same time slowly, leave it on over night, do it at least once a week.  It can rain all it wants, but the roots are in the ball, and that ball can get dry fast.

 With a 90" spade, Id say you'd be close to 100% survival rate.  Bit lower for the 60", but the bigger the spade, the bigger the bill.

 PS:  99% of my customers cannot judge how tall or wide the trunk is by looking at em......I tell em to go measure with "measuring device" and call me back.