Hello
since 1998 I own a 1975 Eriba Familia with four beds and a maximum weight of 690 kg (1523 lb).
Its made of Aluminum on a steel tube frame and a fiberglass roof with a pop-up section.
There you can stand, if you are not bigger than 1.95 meter.
I'm only 1.68 m and can stand with the pop-up down.
It's equipped with stove, sink, fridge and heater.
The Familia is one model in a range of several Eriba Tourings which are since 1957 Made in Germany by Hymer and famous for their longlife quality and light weight.
http://en.wikipedia.org/wiki/Hymer
They are very easy to tow even for smallest cars.
The smallest trailer is the Puck, early models weigh 600 lb, a little bigger the Puck XL.
The following models are all 2.00 m (6.6 ft) wide and 2.14 m (7 ft) high with closed pop-up.
Triton, Pan and Familia are without the 3-ft tongue about 12 ft long with different floor plans.
Next size with 15 ft is the Troll and the biggest model is the 18 ft Titan which is 7 ft wide.
There have been another model named Odin, I think it was like the Titan, but I never had seen one.
The Eriba Tourings are still produced today except of the Titan, but they are heavier today than the early models.
New Erba Tourings are very expensive and for that reason old and used trailers get high prices.
Because my girls growed out of the front beds, I purchased in 2012 a cheap 1977 Troll without kitchen and restored it in a simple way.
If there are questions, don't hesitate to ask. Here in Germany is a very good forum about restorations of that vintage trailers.
Tom