karne - sadly you won't find the danskins any more as I believe they've gone out of business
I have found capezios to be a good substitute though. As far as the Mondors go, the Evolutions (style 3337/3338) are OK quality but I really don't like the colour. The Mondor 3310 ("opaque footed") are thin and nasty, and run really easily, and I still don't like the colour
I haven't tried the Mondor 3350 (opaque OTB).
Re darning them - they can be darned quite easily. I do what skittls does - turn inside out and whipstitch closed. I usually wear 2 pairs for a competition, and it's pretty unlikely that I've managed to hole two pairs in exactly the same place, so the darn really doesn't show from a distance. I have found that the cotton I use can show against my pasty white legs (
) if it's too dark, so if you're fair, I'd suggest using cotton one shade lighter than you think you need. Also the tights fade with repeated washing, so using cotton one shade lighter means the darn won't suddenly show up later.