the only 1 TB notebook hard drive i know of is from Western Digital, but it's a 12.5mm model instead of the more regular 9.5mm...meaning it wont fit in a MacBook. another 1 TB notebook drive is from a brand named Pure Silicon, but its an SSD. and very expensive

. i believe what u meant by 'cpu-like' hard drives are the big ones? you can just call it a desktop HDD..the proper name is 3.5" HDD. Notebook drives are 2.5" HDD. there are also 1.8" HDDs.
most computers today (actually, i think ALL computers) use SATA (serial ATA). ATA (its normally called PATA or IDE) is a very outdated technology. however some shops still sell IDE drives, so be careful. anyway, your best choice now is to upgrade to a 500gb HDD because its widely available and of very good value (around RM280). a lot of us here (including myself) are using a WD Scorpio Blue, another good one is the Hitachi TravelStar 5k500.
about bootcamp, AFAIK bootcamp is for internal HDD. running another OS from USB would be very slow.
i don't mean to offend, but try to learn more on these stuff before you spend ur money on it. i'm just concerned if a shop try to con you. to summarize, what you should be looking for is a 2.5" SATA HDD, the 9.5mm variant.
and yes, both RAM and HDD can be upgraded yourself, but make sure you know what you're doing