Rear shock advice needed ....

Hey guys im new on this forum so, hi first ! Now ...
Ive just rebuilt my '90 ZXR 750 H2 and was after some rear shock advice. I have left the standard unit on at the moment but it is pretty useless (makes funny noise when compressed) I have a few hundred £££ to spend on another rear shock. Any advice of what to avoid/buy would be greatly appreciated !
Thanks in advance
Smithy
Ive just rebuilt my '90 ZXR 750 H2 and was after some rear shock advice. I have left the standard unit on at the moment but it is pretty useless (makes funny noise when compressed) I have a few hundred £££ to spend on another rear shock. Any advice of what to avoid/buy would be greatly appreciated !
Thanks in advance
Smithy