300tdi vacuum pump

Hi, brakes on my 97 defender 300tdi have deteriorated over the last week (brake pedal requires excessive force) to stop vehicle. Removed vacuum pipe from brake servo and put finger over end and started engine, result no suction. Looks like vacuum pump failed. My local LR parts man only has a Britpart pump available.
I have seen various threads about Britpart spares and am not sure if I should fit this part or source Wabco pump online. Anyone fitted the Britpart pump and had problems?

Google unipump. These are more highly regarded I believe. Avoid Wabco.

I have wabco for all the ones I have replaced without issue - but this caught my eye on the bay:-

www.ebay.co.uk/itm/252248988522

5 year warranty .... and not daft money IMHO.