i have a scout model (18" barrel) and i dont fid her to be cumbersome at all. I think the 18" or even the 16" socom would be easy to maipulate in a CQB situation. with out getting into the whole calibur debate (7.62 vs 5.56) if ur unsure of the handeling, there are pistol grip stocks out there for the m14/m1a that would bring the manual of arms closer to the ar15.
Sig P226 .40s&w/9mm -- Kimber Pro CDP .45ACP -- Radom P64 9X18mm Makarov -- Dan Wesson RZ-45 Heritage .45ACP -- Ruger SR22 .22LR -- M&P9c 9mm
Springfield Armory Inc. M1A Scout 7.62X51mm NATO -- Kar 98AZ (1917 Erfurt) 8mm Mauser -- Marlin Model 60 Glenfield .22LR -- Marlin 795 .22LR -- Marlin 915y .22LR -- AR15 5.56x45mm NATO -- Springfield Armory M1 Garand 30-06