The basic SP-01 would be cheaper but since the OP plans to use it for competition the SP-01 Shadow would be better out of the box. It maybe more expensive but you have to factor in what you get for that extra $200+. It has an 85c slide without the firing pin block, 85c trigger which is less curved , lighter hammer and recoil spring, larger safety lever, upgraded competition sight, extended mag release button and 3 mags instead of just 2.
IMHO, the SP-01 Shadow is a better deal than buying the SP-01 then upgrading it.