I replaced these today. The Original Renault one are made by KYB and the replacements i sourced from the local motor factors are also made by KYB but about half the price of Renault ones. The KYB part no. is 344809.
With the right tools and equipment its not a bad job and took a couple of hours.
A few tips:-
1. Undo the 3 fastners that hold the wheel arch liners in place and partially remove the liner to gain access to the top shock bolt. This will make undoing the top shock bolt easy.
2. Use a BFH and chisel to remove the bush from the lower suspension arm. This can be made easier with penetrating oil and a good set of stilsons to rotate the bush if you find its stuck.
3.The nut for the top shock bolt (offside) is difficult to access when refitting. A dab of silicone sealant on a 17mm ring spanner is good enough to hold it in place while you thread the bolt on it.