In regards to the is it 1 or 2 models for "Sharara" I'm no expert but, I believe them to be models from IM@S 2 for a few reasons.
1. Azusa's hair movements.
I will be the first to admit I've never played IM@S 1 but I just spent half an hour hunting down IM@S 1 footage of Azusa.
In every video I found, her hair moves as a chunk. Much the way Takane's hair moves. When she sways, There is little fringe hair moving.
However, in the SFHS video, her hair separates as she sways back and forth.
2. Ritsuko's hair style
In all L4U videos I found of Ritsuko in her Pajama costume, Her hair has "crimps" which is consistent with the fact that she always wears her hair in braids. Her IM@S2 model doesn't have these crimps but slight waves. (She wears her hair in a bun)
3. Hair Color
Both Ritsuko and Azusa have slight hair color variations from IM@S 1 and 2. Azusa's hair is a brighter blue in 2. In one her hair was closer to a Navy Blue than the blue she has in 2.
Ritsuko's hair also lightens up in two. Her color goes from a Walnut Brown to a Chestnut Brown. A little lighter and with more red coloring in it.
Also as far as having a hair style not in IM@S 2, they do the same thing with Miki in "Marionette Heart" for Funky Tune. I've never seen Miki with her hair up (I've seen in G4U in her Yukata but I don't know if that is in actual IM@S 2) but in Funky Tune she has her hair up.
Well that's just my two cents.
