Bearica made my signature and I am very happy with it! She's really sweet too.
This is her thread (click). she's selling them for quite low ^^, aaand revisions are free for later!
You can also make them yourself if you're good with photoshop!
If you go that route you can google "Animal Crossing New Leaf Villager Sprites" and pick from the links. I use welcometoathena's tumblr post (should be the first one) for when I make them.
if you like pixelated styles, you can look up pixel backgrounds on google images and find good ones, i think. if you like the pixel villager icons, those are here at this site and the artist said they were free use. you can put them together using free art programs like GIMP and (my favorite) FireAlpaca. as for pixel text, i'm not sure. lots of people have great sig shops on the forum too!