Should I go out of my way to get 2 identical RAM modules or not?

[rapchee]

I have a fairly rare (afaik) laptop, a Compal FL90. I quite like it, but it only came with 2Gb RAM, I think it would be most appropriate to double that. The thing is, I couldn't so far find the same module in the UK, but I could order one from Poland - well, to be precise, ask a friend to order it, somehow pay him, arrange delivery- so it's a bit of a kerfuffle.
My question is: is it worth all the trouble to have the exact same module (and a few extra £s)?
Edit: forgot to add that the current RAM is a GoodRAM GR667S264L5/2G DDR2 module, if anyone happens to have one in the shed.