I'm not sure about the difference between cupcakes and muffins, I'm still very much an amateur baker;) I do recall seeing those pans you mention, they are probably more solid than putting loose cups on a tray. But since I'm still figuring out how much I like fiddling with food I'm not investing in any more stuff just yet:)

I'm sorry. I'm not experimenting next weekend (as I'm on a trip to London \o/) so you'll be safe for the next two weeks;) Good luck with the low carbs.