I recently bought a Tipro 128 along with some POS caps to play around with. In doing so, I think I have settled on a nice portable layout. 
In fact, a hand-wired, walnut keyboard may be in the works to compliment DSA Royal Navy. I 
really want a Nantucket Fugu to go with.

It may seem a bit cramped, but placing the numpad in the middle makes it very comfortable and its only 1u wider than a 60%.