I like the lamppost one you linked, very elegant!

Try Redbubble, it’s usually loaded with discounts and the stickers come in so much variety

I got a Narnia themed phone case from there, that was subtle and very painting-like, I’m sure you’ll find something you like there

Also, if looking for discounts/coupons use the browser Miscrosoft Edge, the updated version, and high automatically adds them to your cart

A little bit of poking on Etsy and I've found there are folks offering custom stickers (for example, this one), so it shouldn't be too hard to get your quote printed.

      Thank you. I will be checking out one of those custom stickers @mel and I already use Microsoft Edge for my browser @highkingpete, but thank's for the tip anyway!

Child of the King: SonofStone

Ha, love the lamp post one!! But importing it from the US would no doubt cost a lot more than the sticker itself. I will be moving to America some time late this year or early next year, though (for work), so I may have to add that to my list of things to buy while I'm over there...  

@highkingpete, why on earth did I not think to look for a Narnia-themed phone case when I needed a new one earlier this year?? Well, I did find one with unicorns on it, which is close enough, but a Narnian lamp post, or Aslan himself, would be even cooler. I guess there's always next time...