I would get the fixed ones. A tougher choice is between the 15 degree angled wrenches with reversing levers or the flat ones that you flip over to go in the other direction. The angled ones are more convenient, the flat ones may be stronger.

Craftsman is good quality stuff, probably much stronger than GearWrench. However, there is a pitfall to watch out for. According to my 2007-08 catalog, for some idiotic reason, most sets of Craftsman ratcheting box wrenches do not include a 19mm (one of the most commonly used sizes) nor is it available separately. There is a set of four "pawlless" box end ratchet wrenches, (0942447) 8 X 10, 12 X 13, 15 X 17, 18 X 19, for $49.99, that look like regular Craftsman wrenches (not full-polished) but not that this set omits the 14mm. These are flat wrenches that flip over.

Another choice is Snap-on, which have only one major drawback---their 10-19mm set costs about $300.