Welcome,
Gernerly you get a good quality rep from the sellers here, but do your reaserch, in the seller and the watch. if you buy the right one it will work just as the gen. The navis with the sub dials @ 12, 9, and 6 will be you best options as thast it the standard subdial lay out for the 7750 it will be powerd by unless you get lucky and find a 7753 powered one but that will be expencive and rearer than hens teeth.
Have a read of bytors pages