I can think of nothing worse than a 42" computer monitor, especially when you say - with regard to the computer base unit - that "Size is everything".
That said, you might want to consider the keyboard I use - the best I've ever used in fact.
It's not cheap at £140, but it simply exudes quality, and it looks superb. It's less than half an inch thick, has a wonderful key action, and comes with a full set of touch controls which illuminate when you put a finger on them. Included is a circular trackpad that is extremely responsive and easy to use.