It's hard to say. The AC Delco or Bosch will probably be fine, but at the end of the day they are aftermarket parts and they may have cut corners that weren't cut on an OE pump to get it to the $40 price point. Neither brand is all out bad, but they can be hit or miss, especially with so much outsourcing going on these days.
If this is a super clean truck you intend to keep a while, I'd probably spring for the Motorcraft. Odds are you won't need to touch the pump again for another decade, and that way you know the truck is using all OEM grade parts. The original one has apparently done fine over 12 years with the original coolant, and I've never had a Ford truck WP go bad myself, so that seems to be the safest bet.
If the truck has been around the block a few times and shows it, paying $170 more just to get a Motorcraft pump may not really be of much benefit if you don't plan on keeping the truck more than a couple more years.
Another way to look at it, if $200 isn't a HUGE deal for you, just go for it. If a $200 pump will put you in a bind, then the $40 ones will suffice, just with a slightly higher risk of having to do the job again in the not too distant future.
