I use internal PROFI INTERFACE in my grey ZX128+2. This interface use trdos rom maper and big memory 1MB. Actually I use TRDOS roms with ramdisc support and TRD image is in 1MB memory (compatible with russian clones):

http://velesoft.speccy.cz/profi.htm



If you don't need use real FDD, then only IDE interface can be connect for import/export TRD images to ZX+2.