I have a CMMG 18" SPR Midlength with a YHM single Picatinny gas block. It currently has the M.I. non-free-float handguards. I have attached a Harris bipod using the Larue adapter. However, my reading here indicates that this will most likely result in a shift in the POI. I am wondering which free-float system would work well with my set-up. I am not very mechanical and am willing to ship the upper off to have a system installed if that would be best. Thanks for any advice you can give me.