I had an a350 back in the day. As I recall, there weren't many accessories for the DSLR. With it being the old Minolta A-mount, you can find old Minolta Maxxum lenses (1985 and after) that will work on the body.
Since the hotshoe is also the proprietary Minolta AutoLock, you might search for a Vello Minolta to Sony Multi-Interface shoe adapter to use more standard flash units.
I tried using a CF to SD card adapter, but found that they were always very slow... Just better to use a decent CF card (though, they may be getting harder to find).