If someone is interested in testing x64 Windows installers with x64 java, you can still grab them here (they will disappear once more builds come out) https://bamboo.igniterealtime.org/browse/OPENFIRE-NIGHTLYWINDOWS1-292/artifact/shared/Project-Windows-distribution-files/ You can even install it on top of your x86 version (just need to point manually to the installation folder). Of course, do backup first! But it worked fine for me.
You can report issues with x64 installers here 64 Bit Windows Installer feedback