Caseking.de may be a great choice as well.
I often buy from Amazon.de (sometimes it, es). Shipping within europe is very affordable and at least no import fee.
Regarding your initial question, there's no "void if removed" sticker other than on the cpu and no way for them to see if you opened it as long as you use the correct tools. Swapping SATA peripherals is very easy & common. You'd be very unlucky if it stopped working after such a simple mod and that the warranty was refused. That being said I totally understand the "you never know" argument especially in such an environment as yours.
BenM98 reacted to Call_Me_Daddy in Sata 1 SSD?
