Unless you're planning on more than 2 OS( I have 3, xp32, xp 64 and Vista ultimate 64), you wont need any boot managers. While installing XP 64, you will be given the choice. after install, you can choose which one to boot up, or have your choice auto boot after a set time (I set mine to five seconds). And yes, XP 64 is perfect with VI , and as mentioned above it will use all the memory available.