[Transmission] Gearbox / overhaul replacement experiences pls

[Robho]

I have a 2007 1.6HDi Peugeot Partner with a 'thrumming' bearing noise, after several tests I'm told is most likely the diff bearings.

Appreciate any feedback from those who have removed the gearbox - had their own overhauled / bought a replacement (etc.) to get an idea of the options and any pros and cons please (especially reliable suppliers - I'm in Sussex).

thanks.