Based on my experience in that business, from many years ago.
I prefer higher-quality aftermarket lock actuators. The best aftermarkets were originally Swiss-made, and then the exact same design became commonly Asian-manufactured. In the years since, when I've tried retro-fitting used OEM actuators, the fitment is fiddly and they don't seem to hold up as well as the older aftermarket ones. I've found that aftermarket is easier to install and more reliable in operation.
I've never seen an aftermarket "universal" power window kit that was worth a crap. I'd definitely source some good-condition OEM regulator and motor drive assemblies to transplant into the non-power doors. OEM units perform better here, and you have very, very good point on replacing the motor, when it becomes needed. I *think* that these OEM-style assemblies are available new, but new parts quality has gone to hell in a hand basket recently. I'd trust a good original assembly over a newly-manufactured one.
On an upgrade from manual to power installation, I'd also use OEM switches, and just make up a new harness, routing it around the front of the engine bay like it was done originally on the first and second generation trucks. OEM switches work good, are common enough (new and used), and they simply look the best.
Another consideration is, when doing this upgrade, it's also a lot easier to add remote keyless entry at the same time (which also expands your options on how the door lock switches can be wired). It would also be very easy to add a later automatic down module to the driver's window, if you're so inclined.
