Does anyone have advice for finding the best deals for a long-term stay? I'm headed east for a school program and the 60-day stay seems to be hindering all the good deals.

tl;dr version:
For example, Egypt Air has good deals now from JFK to CAI with travel dates in June, but if I return in August the cost is high.

I'm PHL and prefer to depart from here but JFK/Newark are options. IAD is a little more difficult to get to. I want to fly to AMM or CAI and depart from either or TLV. My aim is to depart PHL around June 3 and begin the return flight on August 2 or 3.