I have tiger endlers, not *inside* the beltway, but just off the Dulles Toll Road and could be persuaded to meet someone. How many were you looking for?
I have some that I bought earlier this year from Msjinkxd, I think, at an auction. They're just starting to breed, however, so it will be a few months until I have some for you. On the plus side, I do live inside the Beltway, near Walter Reed.
I'll pipe up for my daughter... she has some that she bought at auction - breeding little buggers! I think they are from Jinx, too. We're way out in the country in VA where WV, MD and VA all converge - but we'll be at the meeting in Oct.
If you are looking for true Endlers (Poecilia wingei - yes they have been given their own species name) I suggest being very careful since many lines of Endlers are actually crossed with guppies. Europe is the hotbed of hybrids; however, there are many hybrids floating around in the US too. In most auctions I've attended over the last couple years I've seen more hybrids than true Endlers. Check the Endlers websites for know and recognized varieties of Poecilia wingei. There are many phenotype populations that are line-bred (homozygous)(some well beyond the original collected varieties). Interestingly the fish in the lagoon(s) are homozygous with one color pattern found in each location. Heterozygous populations of true Endlers have resulted from folks mixing fish collected from the various locations in the lagoon(s). True Endlers are really ony those from the the narrow group distributed by Kallman a decade after Endler collected them. These are all homozygous - some folks are crossing these lines for color and pattern variations because some of the early literature alluded to heterozygity but the majoity of the variations out there are really guppy hybrids. True Endlers have a dorsal fin made up of seven to eight radiating spines and under the microscope they are black - hybrids don't.
I don't want to start a debate over who has or doesn't have true Endlers nor am I implying that some of those offerred herein are not ture endlers.