@alexh
No it's not. It's named FastATA 4000!
http://www.elbox.com/products/fast_ata_4000.html
Please look at the shop site
here, were the FastATA 4000 is in fact called
Fast ATA 4000 MK-III, so AndrewBell hasn't stated anything incorrect and amigakit.co.uk hasn't mislabeled their item. However, the MK-III term is mostly used for the Amiga 1200 version, so it's easy to get it mixed up.
As for the Buddha; you might think it's not a useable device, but the OP hasn't stated if he has a A4000D, A4000T or a towerised A4000D. If it's a towerised A4000D, the OP might want to have additional harddrives and/or CD/CDR or whatever installed, and the Buddha beats the internal IDE controller pretty easily then.