I would suggest the Samsung F3 Spinpoint, but for some reason Newegg.ca doesn't carry it any more. If you can find it around where you live that would be great since it is faster and more reliable than other drives.
For the 5850 I think you should be fine. The only worry is that the GPU fits inside the case but a 10.5" card fits inside the Antec 300, so unless I don't know how to count, I'm sure the 9.5" 5850 will fit inside the case. The only thing with cases is making sure your parts will fit, airflow, and whether or not you like how it looks. Personally I like a full tower because I prefer a lot of room to play around, but like I said, it's all personal choice. But after that little rant, I'd say that the 300 is a pretty good case, especially for the price.
To clear up that confusing mess up there, no, there is no problem with that case.
Anytime. It gives me something to do at work 'cause the government doesn't give me anything to do. (FYI, I'm in Canada too, these are your tax dollars hard at work )
The GIGABYTE GA-P55M-UD4 might suffice, even though it's micro ATX. The difference here is that there are less expansion ports and SATA ports. If you'd like to keep the full ATX experience you could go with the GIGABYTE GA-P55-UD5 but this one is a bit more expensive (but still within your budget).
You could also go with the ASUS P755D PRO, which is a lot like the GIGABYTE UD4P.
Note: I know it looks like I told you not to use this one, but when you mentioned the P7P55D in your first post I assumed you meant the LE, but the PRO will work just fine for your needs.
Well, the Samsung is a little bit cheaper and actually runs faster. It uses 2 500GB platters instead what WD uses (something with greater than 2 platters). The two platter system offers a lot faster read/write speeds overall.
Well, the Samsung is a little bit cheaper and actually runs faster. It uses 2 500GB platters instead what WD uses (something with greater than 2 platters). The two platter system offers a lot faster read/write speeds overall.
Im pretty sure the WD 1Tb is a 4x250GB platter drive.