on go post on the US/IOA board - they have several offsite experts there.
I would stay onsite at Univesal - but that is way to expensive for your budget.
the problem with Universal is that it is not on either Lynx or I-trolley - it use to be on I-trolley - so you have to stay really close to get back and forth.
at the prices that WDW now charges for one day - I would think again.