I wear either Argyll hose in my tartan, or hose complementing my tartan's primary color (green), with flashes to go with my tartan's primary stripe (red). I've got a set of tartan flashes which came with one of my kilts; I've never worn them. I never wear white hose unless playing with my band (part of their uniform, *sigh*).

Your fur sporran should be fine. Mine's a full-face red fox. Horsehair sporrans are generally considered military dress, mostly worn by pipers.

Your black wingtips should be fine. They resemble the MoD brogues issued to regimental pipers in the Canadian and British Army.

If your events are indoors, don't worry about a bonnet unless you're a piper or a member of an honor or color guard. They're considered "under arms", and therefore don't uncover indoors, as a gentleman would be expected to. Outdoors, I'd opt for a balmoral which goes with your kilt hose, without dicing.

You might want to dress up your Eaton jacket with some traditional silver buttons;
, so you're not mistaken for a waiter.

Get a cheap set of black studs, too; they're part of formal dress. Your shirts may also need cufflinks.

If you can afford a fancy skian dubh, ghillies (learn how to lace them; they're not laced up the ankle like girl's sandals), fancy sporran, etc., by all means; knock yourself out. However, if you only go black tie once or twice a year, this should do you.