Jude-
Welcome to the Forums...
I can highly recommend classifieds here, as well as
www.airstream.net and
www.rvtraderonline.com for web-based searching....
Surprised nobody answered your question directly yet ("What would you buy for $12,000?").. Thought I would take a try...
Unless your '95 Ford is a monster truck (3/4 ton HD Diesel etc..) you're probably limited to trailers of 25' or less behind a Ford F150.. Really older ones are either pretty rotten ("As Found" condition according to vintageairstream.com ...) or elegantly restored, and if you can find a restored model that could work. In 1995 all Airstreams got wider and heavier, and since it is just you two, you might not need the extra weight and width...
I'd look for classical Excella 25 from 1986 through 1992, with rear bedroom. Some have queen bed on side, others have twin beds. Choose wisely, as they're hard to modify. Prices will run from $11K up, depending on condition.. You might also find a 22' version, which also offers double axles. Bathrooms varied between side bath with separate shower and rear bath with "wet shower" where entire bath area gets wet when shower running...
There's an '89 25' Excella on classifieds here or asking price of $12.5K... Others include earlier Safari's or Trade Winds in range from 23' to 24'...
John McG