Hello from a fellow Scott!

Good on you for taking some dancing lessons.

I wouldn't worry about getting ghillie brogues. Totally unnecessary. Your dress shoes should work fine.

As kilted2000 said, the kilt can be considered a substitute for trousers (or vice versa), so in addition to the kilt and dress shoes, wear kilt hose, flashes (may or may not be needed if your hose stay up OK even with active dancing), and sporran with sporran strap (probably turned to one hip or the other while dancing).

Your day sporran should work out fine, but you may want to consider getting an evening sporran. A full mask sporran could be worn all day. (Some may debate that, but that's what I was told by a Scotsman with some experience.)