I use one (intern model) with an "Escom" A1200 and it works great since years... it's a good hack !
My A4000 use 2 HD Chinon floppydrive (DF0 and DF1) but one fails to read 1,76 Mb FD some time to time...
http://www.schatztruhe.de/ (aka GTI) still sells DD disks too !