Red background for sure. Multiple pictures on the cover works to show the range of items you have. Has for the halloweenie part, that is a hard call. But I would suggest that once you decide on a cover style that you keep it simular year to year so that it can be easily picked out as yours. Maybe a color change each year but the same overall style. I was told that you should be able to identify a catalog from across the room without reading the cover. Almost like its a logo. And keep it simple, just title and date, readable in a few seconds. Good luck with it.
I to prefer the red one. My partner took me to task the other night gor making green note book cover because it didnt stand out enough. The cover is nice just enough to convey the content without being busy.
I just saw this post so I thinking the cat's rather then red background, the red looks a little too sinister and if you costumes is you #1 seller (based on the size of the cover picks) some my go for a more friendlier cover for thier family costume picking. Also the cat's is closer to your current web home page colors. That's my thinking.