I'll try and do a pic that shows the field of view with mine. Meanwhile, a quick Google found this site in the UK with some supplied to meet the needs of the disabled. I'm definately not including you in that group James!
http://www.mobilityconversions.com/mirror.html
For the USA
http://www.nextag.com/mirror-panoram...ew/stores-html Lots of choice there. I think your multi mirror was one of a type they called "Wink" mirrors. I know what you mean about them being a bit overwhelming, even my one has a rather dominant view until you get used to it.
I have a friend in the same situation as you and he has a small kidney shaped wide angle mirror mounted on the dash just inside the A post to augment his outside door mirror. I don't know how well it works.