Have you considered asking your LFS if they could get some in. Tbh, I actually preferred neons and went into the shop with the full intention of buying some, but the cardinals seemed much more brightly coloured.
I think I'll be happier when things have settled down a bit - the more I think about it, the more I'm sure the ammonia was up this morning. It's true I didn't do a full qualifying week but the ammonia had been zeroing in 12 hours for god knows how long. I'm wondering if it's my plants that are causing it or something, since when I had I put them in my tank before, it was the first time in ages I didn't get 0. I hope it's me being paranoid, as I just can't see why adding plants would make my bacteria stop working unless I'm missing something.