How about these Rob?
LINK.
I paid less than £60 for a pair of dampers, but they lasted not particularly well.......something like this
THIS about 25K and 11 months.
However if you are willing to take a chance, and at the price with a 1 year guarantee, how about
THESE
To be fair, "OEM" is meaningless out of context, the actual OEM to Rover were Delphi, are the ones you linked to from DMGRS, are these Delphi??
Pay your money and take your chance is my recommendation, or ask the question of the supplier first to see what the answer is
Brian