Well I haven't bought a SC DSTWO from this site but I bought a 3-in-1 Expansion pack and it was fine.
r4igold3ds.co.uk has plenty in stock. £35 without the SD card. They accept paypal payments but it is via a wierd method. You go through the payment method and then you have to wait for them to e-mail you a link to pay them the money. The e-mail took me a day to go through and I was a bit suspicious about the method, but it went through fine and I got my product with no real problems.
The shipping said it takes 4-7days I think for UK delivery, but it actually took much longer than that, over 2 weeks for me. I'm not surprised because it was the christmas tiem (I only got it a few days ago) but if you van wait that long they should be good.