Hi Steve,
Stick a copy (about £50) on the first motor that comes off the waste tank (one closest to pump). It always takes the brunt of the foam etc that inevitably will hit your motors one day. Unfortunately, copies don't fit too well in the 2nd motor position unless you want the machine to sound like a jet engine. Just keep an original lamb there and replace brushes etc.
Unless you totally flood the machine it will last there for years, but you will run through 2-3 copies in this time on the front motor. Not that the copies are worse, just that the front motor is vulnerable.
Tried to lookup woodbridge site to get a motor number for you, but they dont seem to list them (dont buy from them btw i have been waiting 2 weeks for a shureflo motor brush end...6 calls, still not here)
If you do end up running 2 1400w motors then i would suggest you make sure the wiring to the choke is ok or it will embed itself in the body of the machine as it gets rather hot.
Graeme
Access Cleaning Solutions
PS Rem you need no flange on your motors and best to get the motor gasket at same time, also dont tighten it up too much or it will grind in high vac situations.
Edit: I cant actually find anyone now Woodbrige and Olympic dont stock the copies, but i have 3 so they deffo exist....