>>7324225>how to find a japanese model kitJust search "Bandai General Grievous" on Ebay.
Building isn't exactly rocket sciene unless you can't even handle LEGO though painting is a bitch.
The neck looks way too long on Hasbros figure, the kit works way better if you want to go for the Genndy look. Figuarts is also an option and I assume that it will finally release either this or next year.