I believe your in the Philly area, correct? You can try Limekiln Ponds & Gardens (glenside, mont co). They can rehome the common goldie in one of their ponds. Number: 215-884-5928/ firstname.lastname@example.org
Theres another place in the city with an indoor goldfish pond that takes goldies as well but I will have to find their name. You can keep the fantail with lots of water changes until you can upgrade his tank if you commit yourself to his upkeep. Craigslist Philadelphia has lots of good deals on tank upgrades! Good luck!!