I am no HDD expert. but with the cost of HDDs I would say pickup 2-3 1 to 1.5GB drives and RAID them 0 or 5. 7200RPM is plenty fast for HDV or standard compressed HD video. Look for a good cache amount; 16 or 32MB.
Maybe someone can explain why you should buy a 10000RPM drive.
HDV via firewire is no bigger than DV in bandwidth requirements. single drive is fine and 10k is not needed
uncompressed requires a minimum of 2 drives in raid 0.
better off with 2 1TB 32meg seagates/WD's in raid 0.
bear in mind with ANY drive once you get past 60-65% full your speed is drastically reduced.
250G and 300G is way to small.