I too insisted on a 5-speed when I started looking for an Eagle. It took me a couple of years of daily online searches (Ebay, Craigslist aggregators, etc). I bid on a couple of ratty ones during that time, but dropped out when they got over $3000. Then one day, there it was: a good-looking '84 Sport wagon with the 5-speed, being used on a farm in Idaho, with a 'Buy It Now' price of $1000! I've never clicked on a button so fast in my life. Then it took another $1100 (and many gray hairs) to have some interstate shipping pirates deliver it to me in Sugar Land.
I'm glad I held out for a 5-speed. Not only is it much more fun to shift 'em yourself, the tranny is probably the only part on the car that has been absolutely bulletproof, with no maintenance required other than filling it with Royal Purple when I got it.
Good luck with the search...
JB