I'll cover 4 good Pokemon for a hail team.
1) Abomasnow
Abomasnow is vital for a Hail team, as he sets it up with Snow Warning right away. It is one of the two Megas that function decently in Hail (the other being Mega Glalie, who lives only to Explode.) So here's a Mega Abomasnow set:
Abomasnow @ Abomasite
Ability: Soundproof -> Snow Warning
Brave Nature
252 HP / 252 Atk / 4 SpA
-Leech Seed
-Wood Hammer
-Ice Shard
-Blizzard
2) Walrein
Walrein serves as the best of walls under hail. It gets Ice Body and Aqua Ring, and it can hold Leftovers, allowing it to heal 18.75% of its health each turn. Here's a Walrein moveset:
Walrein @ Leftovers
Ability: Ice Body
Calm Nature
252 HP / 252 SpD / 4 SpA
-Substitute
-Aqua Ring
-Scald
-Ice Beam/Blizzard
The only reason you should run Ice Beam on this set is if Hail runs out by the time Walrein's on the field,
3) Mamoswine
Mamoswine has great HP and Attack, so I think he fits the role of mildly offensive Hail setter.
Mamoswine @ Focus Sash
Ability: Snow Cloak
Adamant Nature
252 HP / 252 Atk / 4 Def
-Hail
-Icicle Crash
-Earthquake
-Knock Off
4) Regice
Regice has awesome Special Defense and respectable Defense and Special Attack, but his Speed is trash! So here's an offensive RP Regice:
MY BODY IS REGI (Regice) @ Life Orb
Ability: Ice Body
Modest Nature
252 SpA / 252 Spe / 4 HP
-Rock Polish
-Thunderbolt
-Ice Beam
-Focus Blast
That's all I got for now, hope I helped!