Hi, David,
There's one thing with some of the above suggestions - when in use the larger pens cannot be capped. In other words, when you unscrew the cap to use the pen you cannot screw the cap onto the other end. This means that the cap will have to be held or placed on the table. In turn, this means that if you put the pen down it has NO clip attached, and therefore the pen may roll off and drop on the floor!!! Best check with your mate re what type of pen he wants.
Bob.