Having done a good bit of work on these (including developing a correct delay circuit which can be found here but is not a Tech Tip), I can tell you 2 things: paying more won't mean your wiper will run better nor quieter and 2...the ones sold on eBay work just fine and may need a bit of adjustment of the brackets. Or not. Some of them fit straight on and others will need to be bent just a wee bit to make the holes line up perfectly.
But as I said first, the wiper motor is inside the cab (as opposed to on the other side of the firewall as was common in vehicles made from around 1955 on) and you will naturally hear it. I've tried to minimize this by using rubber mounts, rubber washers, insulation around the motor, etc and you can reduce it to a degree. I get questions occasionally about this and there's no magic bullet...nothing you can do (aside from chopping a lot of stuff up to move your motor outside) will eliminate the sound of the motor and the dashboard being metal just magnifies that noise. The electric motor makes a noise completely different from a vacuum motor and the mechanism needed to stop/reverse the motion doesn't help. Otherwise, good luck.
