I'd take a look at the internals of the t.bone SC460 if you can find pictures of one, or a schematic, because it actually does have a cardioid/omni switch. But you'll also need a dual diaphragm capsule since omni on an LDC is cardioid+cardoid. Omni also isn't great on an LDC. It's usable but it's not completely non-directional if that's what you think you'll be getting. I wouldn't do something like mic a group with an multipattern LDC in omni because I find the sides suffer a bit. I haven't done any sort of scientific testing, just speaking into my multipattern mics on omni from different angles, and it happens on my AT4050, CAD M179s, iSK BM-600, Behringer B2 Pro, and my C414 B-ULS. Maybe it's better at a distance but close miking I don't really care for dual diaphragm omni or hypercardioid.