Replacing One Damaged Tyre

[PookeyMaster]

Hey guys,

So last night as I was driving home at 3 in the morning, I came around a corner in a roadwork zone and my right front wheel clipped a rather large rock. It seems it came out from under the concrete barriers at some point.

The rim is fine, just a small mark like a gutter rash (it was untouched before this :( ) but as soon as I took the wheel off, I could hear the air leaking. While I thought I missed the rock, I've obviously just clipped it and its cut open the sidewall of the tyre.

So my question is, all 4 tyres (OEM) have about 25% tread left. I was planning on replacing all four with Nitto Invo's when they were worn in probably 2-3 months. Do I replace just this tyre and use the spare on the other front wheel (so they're both new tyres on the front) and just replace the other two rear tyres when they are worn out? Is there any issues with mixing tyre brands or will it be best to get another Dunflop to replace the damaged one (which I would run with the spare on the front)?

I have photos of it, but I'm 99% sure its not repairable.