I do think the extra for a hybrid drive is worth it. In your case you can't add a second drive via SATA so this is your best option.
The only thing you do need to watch out for is SATA I/O speed. Your systems SATA I/O is SATA II (3 Gb/s) This HD offers compatibility across SATA I (1.5 Gb/s), II (3.0 Gb/s) & III (6.0 Gb/s) others might not play well (in case you change your choice).
Go for it! you'll be happy with the speed improvements.