Ultitmate training is very useful as it gives ya lot of things like tendo frags( in total 76 are collectable) ,cursed charms ,rainbow magatams ,loads of coinsetc.

Now for
Minato or Speed training you have 6500 reccommended intiative instance as final point(no more training in speed will be available after this point).
Mei Terumi or Force Attack training you have 52.1k recommended power as final point(no more training in speed will be available after this point).
Raikage or Survival training you have 52.1k recommended power as final point(no more training after this point)
Challenge the limit ends at 51.5k recommended

Lineups for trainings
For Minato training use high buff lineups like- lightning main barrier lineups ,water main barrier lineups etc
For Raikage training use immortal team like- kimimaro-water main-tsunade -kabuto(this lineup has many variations but healing tips passive is mandatory)
For Mei training use again high buffs lineups-lightning main barrier lineups ,water main barrier lineups etc

These links are some good lineups for water main and earth main
https://www.youtube.com/watch?v=ie--say7U0M -- for water main lineups
https://www.youtube.com/watch?v=Ezr0btQEI2k-- for earth main lineups

also check the easiest hidan strong approaching method-
https://youtu.be/hruF7_tBBuk