You may want to consider a compromise.
You could buy the boat in the Great Lakes
, get her to Chicago, take down the mast
and take part of the Great Loop trip by going down the Illinois, Missippi, Ohio
, Cumberland and TenTom Waterway to pop out in Mobile.
Sail the Gulo over to Houston
or Corpus Christi after you step the mast
in Mobile and then have it trucked to San Diego.
You'd get the adventure of a parial water delivery
and a worthwhile compromise on the distance and complication of the Panama
For more info on the Great Loop, check out How to cruise America's Great Loop
or America's Great Loop Cruisers' Association
Even if you wanted to take the longer way around by water
, this would be a better "downbound" than the Erie and ICW