After revising his Heat loss calculation for my temperature changes, he came back with a 3.5 ton system. Unfortunately Trane does not make such a unit in their 16 SEER or 19 SEER systems. So by default, if we agree with his numbers we need the 4 ton system.
So now the question is do we go with the 16 SEER (Energy 70% Stage 1/30% stage 2) or the 19 SEER (50/50 split). Its already costing a bunch more than I thought. The 19 SEER 4 ton is about $1000 more than the 16 SEER 4 ton...I would guess a no brainer.
Thanks for everyone's help.