Which shocks?

I expect this has been discussed many times, but here we go... I have been rustproofing the chassis, and now I have come to the rear shock absorber mounts, which were an advisory last MOT because of surface corrosion. So as I will be taking off the old shocks (which have been there at least 10 years) I thought I might as well replace them. I can see that OEM ones are available, and also Terrafirma for about the same cost. The old girl is still on her air suspension. Should I just replace like for like with the OEM shockers, or go for the Terrafirma shocks. I must admit I would like a little more sharpness and less wallowing around the twisty country lanes. Will I get that just by going with new OEMs, or ... or... What have others found?

I run terafirma and old man emu
The old man emu are better