If I were to use an external hard drive unit with my A500, then I would surely go for the Derringer.
If I wanted everything set up internally just for the sake of saving desk space, then Viper 520 (or better yet the rare 530).
Ideally, for the cleanest fix of all, an all-in-one SCSI controller and accelerator solution, the GVP A530.
I'd stay away from the other choices. :-)
Oh yeah, and I'd probably go for an A500+ unit as it already supports 2MB of chip ram expansion, without the need of extra hacks added on for this function.
