Ability Grouping?

I work in a small charter school, there are 36-8th graders that are split into 3 homerooms of 12 students.  The 7/8 science teacher and I usually decide the 8th grade classes since we teach them as 7th graders.  Usually we split them up based on personality and behavior.  This year we are toying with the idea of ability grouping to an extent.  Of our 36 kids, there is a bottom 12, these students consist of sped and ELL's along with a few who it just takes a little longer to "get it".  We want to put these students together in a HR (HRs travel to every class together) and evenly distribute the rest between the other two homerooms, meaning no "high level" class.  I have such conflicting thoughts on this based on the research showing how bad this is.  However, I truly feel that we (8th grade teachers) would hold these students to the same expectations as the other two classes, its just the way we would deliver lessons and structure the classes that would be different.  I feel that we would be giving this class the chance to think for themselves and show them how excellent they really can be!

I guess I am looking for feedback from others that have done this.  Does it work, am I right to be hesitant?