Ignoring what i have posted up above, the next thing i will be getting is the disk drives... but i have a question. (again...

)
my motherboard apparently supports standard SATA and also SATA-300. My question is simply, would it be better to get a pair of these:
http://www.scan.co.uk/products/produ...oductID=265758
or these:
http://www.scan.co.uk/products/produ...oductID=265764
Ignoring the storage capacities, as faster load times are required for large files, which would be the best performing? SATA-300 seems to have double the data throughput of regular SATA but would that matter, due to the lower spindle speeds? Do the two counterbalance each other and have no obvious advantages over each other?