What year truck?
Your looking at aftermarket fenders, normally their much cheaper and panel fit & finish show the reason for the lower price.
If your trucks over 10yrs old finding oem will be hard, oem will have the holes and also fit better and have better panel fit and trim line-up.
Depending on yr model you might be better off sourcing one from a recycling yard out of the Southwest where rust isnt as much of a problem.