Seagate, Maxtor, both good.
Important to go for the high speed - 7200 rpm - which you have. When I build my dream machine in the winter I may go for SCSI 15,000 rpm odd to provide the video data throughput quickly enough.
No dual boot will be available from just fitting a second HDD but you should keep the old HDD as the second IDE device for storage; however, if it is noisy, maybe it's trying to tell you something and you should think about changing soon!
If you've got access to Partition Magic, consider fitting the new drive as the slave to the original and doing a partition copy of the complete existing operating system partition to the new HDD. Make it active and shut down. (Making it "Active" is a very important step as I have learned).
While you are doing this, don't alter the existing Drive/Partition in any way in case you want to revert if something goes wrong.
Switch slave and master drives (ie jumper settings or cable positions) and, with any luck, when you next start up, your new HDD will be driving the show and you will have an Uncle Bob.
{Edit for a PS} Just thought about the effect of such a hardware change on the "Registration" of your Windows XP with Microsoft. Will XP run if it thinks it has been installed on a different PC because the HDD is different?