forend Military Standard 1913 rails

[Sacamuelas]

Looking for suggestions/opinions on purchase of handguard for a personally owned .223 Bushmaster A3 w/16" m4 type barrel. I want a free-floated forend system to counter the effects of adding a weapon light/etc.

I have been looking at the Knight, SIR, Bushmaster, and surefire rails...

Any practical reasons that I should go with the higher priced Knight or SIR system for a civilian/police type application. The list price variance is $350-400 for the SIR/KAC verses $125-150 for the BM or Surefire.

Looking at the latest Bushmaster catalog, it appears they have started making a new 2nd version that has the rail that includes the attachment over the A3's upper rail sort of like the SIR system. Is this type setup significantly better? It is $235 verses $135 MSRP?

Note- I am not LE, however, this particular weapon may be used as a patrol rifle by a close family member once the newness wears off to me. Gotta take care of baby Bro's.