I have a 2008 Jayco Penguin Outback, love it, theres so many things you can add to it, its all depend on $$$$$ budgets, have a look at what some people are adding during the build phase in the My Camper Trailer section of this forum, eg 2nd water tank, upgraded suspension for heavier loads, batteries, solar panel etc.
I bought mine 2nd hand in jan for $16K, with 180W 36v solar panel, GSL MPPT, GSL DC-DC charger came with it. I've since added a 2nd battery as it only had 1 battery, added an interal and external tap connected to a pump to the water tank. Removed all the incandescent bulbs and replaced with T10 LED globes, they use heaps less power pity jayco dont do this as standard (or do they now?)
Just removed the Dometic RM-2350 3-way fridge and replaced it with an Engel ST90-F compressor fridge today. If you are thinking of a 12v compressor fridge get jayco to do it for a bit more. It took some work getting it in as i had to use different rubber feet to reduce the Engels height and plane down some side panel to widen the hole to fit it. (i'll be starting a thread about this install soon and upload photos)