ntfs is much better imo. with an 80 GB hdd, there is no question that ntfs is better suited for it. If your boot up it slow it is most likely software based. Clear out some, if not all, of the apps that are loading on startup.
You should have a look in our XP tweaking guides :)
WinXP Tweaking: From Reformat to Relax
WinXP Tweaking: From Relax to Righteous