Pre-emptive tl;dr: No, that's a Really Bad Idea?.
The 64-bit edition of XP is rarely a good choice. Only professional is available in 64-bit, and since it was used so little many devices simply do not have drivers for it. You cannot use 32-bit drivers on 64-bit (cannot, period, no dicking around will fix that), and drivers for a newer OS may not work right, if at all.
There only reason to go for 64-bit XP is if you are REQUIRED to run a program that does not run on Vista/7 (such as for work, meaning your income depends on it) and it cannot work properly with only 4 gigs of total memory.
Just accept the fact that time flows. XP is almost nine years old, and new operating systems are not going to be XP. Furthermore, look at it from a security standpoint. What happens when a product stops getting updates? Any security holes in it stay in it. As soon as XP stops getting security updates (it's already off mainsteam support!), crackers and such are going to be SLAMMING the net with exploits designed to use those security holes to compromise your system because they will never be fixed.
Going for 64-bit XP NOW is stupid unless it's a requirement for a work environment that your livlihood depends on, and you'll keep it disconnected from the net.