I used what I had - parted out an 84 Impala police car I had. Mocked up the mounting, tack welded in place, made linkage to fit. Works perfect! I mounted mine on p***. side to de-clutter behind the gauges. Final weld in place, re-mount and adjust linkage for arc sweep and parking. And now I can always replace the motor at any parts store!
Yup! I put a microbus motor in my F100 years ago... piece of cake to mount, and compact for ease of installation...
It is best to modify/adapt an automotive unit. The old replacement units for Model As and such from Taiwan,China, are weak and don't really do the job. The older ones from Japan are much better. Another possibility is a motorboat wiper motor, often chrome-plated, occ***ionally two-speed, make in America or Germany.
My wipers are over the windshield. I eliminated the overhead motor by using a cable driven Lucas setup from a Jag/MG/Austin. The wiper towers can be custom spaced by subs***uting brake line for the outside tubes. I was able to mount the drive motor on the kick panel out of the way. I bought 3 setups for $15 on Ebay. 2 speed with park and you can use an intermittant controller too.