To flash either rename to PG86IMG, place on your sd card and then reboot to the bootloader; or you can use 'fastboot oem rebootRUU' followed by 'fastboot flash zip PG86IMG_eng-hboot.zip'. A list of the available commands can be found here.
hBoot 1.04.2000, mirror - MD5: 3348C361FED927DABB853E49744BD7F2
If you would like to go back to the SHIP one you can download it here. The process to flash it is the same except over USB you can do it straight from fastboot without RUU mode.
PG86IMG_1.40-hboot - MD5: 1B994699EA226390B47282BCB54088DD
For more versions of hboots including hacked ones check out ramjet73's post here.
Thank you to the AlphaRev & Unrevoked teams for getting us all S-OFF! I also want to say thank you to TeamWin for making the wait bearable by getting us root and to everyone who has spent time ripping this phone apart.
Also thanks go out to SolsticeZero for being a guinea pig and making sure it flashed correctly