Where do you get ice type Pokemon in sapphire?

Well, there is Shoal cave on route 125.

In that cave you can find spheal (water/ice type) and in ice room of that cave there is snorunt (ice type). Also there is legendary Pokemon Regice which you can find in Island cave on route 105. If you want to get Regice you must finish regi puzzle.

First you must catch Relicanth (underwater route 126) and Wailord (fish with super rod on route 129 or evole wailmer up to level 40).Relicant must be first on your team and wailord last. You need to teach some Pokemon TM DIG. Now you go to route 134, the one with currents.... come in from the east side and navigate them to the south west until you hit a bit of land that's capable of you diving into, once underwater follow the land through til you come to Resurface there and you'll

be inside a cave, go up to the inscription and read it. Then use dig. Go

into the room that's just been opened up

Here make Relicanth the 1st Pokémon in your team and Wailord the last,

read the inscription at the end and the caves will be opened after an

earthquake. Regirock should be found in the sandstormy desert in Route

111. In the mountain, read the inscription and do the following: Go Right

Twice, Down Twice and then use Strength and Regirock should appear. Its at

Lv. 40 so be preparedan inscription that look like its in dots.

Regice, the second member of the Regi-trio, Ice Type...After doing the

above mentioned events, fly as close to route 105 as possible, most likely

to Muro Town. Surf North-west and you will encounter a cave similar to the

one you found Regirock in. Enter it, this task is pretty simple, go to the

middle of the wall with the 'braille' inscription in it and press A, wait

for a little bit and a door should appear...this could take several

minutes so be patient. Go in and Regice will be there. Once again, its at

Registeel, the final member of the Regi-trio, Steel Type...After doing the

above mentioned events, fly to the town that's to the east of the Safari

Zone. Go to the Safari Zone, but instead of entering go west until you

discover a staircase, go up this staircase and you'll enter another part

of route 120 (where it's raining), there will be another mountain. Go into

this one and once again you'll find an inscription, read it and head to

the dead center of the room and use Fly. A Path to the next room should

open, go into it and Registeel will be there waiting. Its at Lv. 40