I would put "Black Sheep" bikes on your short list. Go to the website and look under "dream" and "out of step" model sections. Look at the S-Cargo and Long Tail models. A custom combination of these two bikes is what you seek ? Should cost around $8k. Go ahead spend and enjoy, youv'e earned it.

While I can understand others suggestions for cheaper rides that will get the job done that doesn't seem to be what YOU want. Hope this helps.