noclass_nick: Thanks for the heads up mate, yeah the postage is a nightmare! I was trying to order some DS cases from the US too and ran into the same issue. Ended up using cassette cases.
Arseem: How do the double wide DVD cases go with holding the carts and manuals nicely? Do you do any additional modifications etc?
Usually no additional modification, I just remove inner trays.
Only if manual is thick I remove the disc holding clips from the back and front as well.
Carts sit loose in there, if you want them to stay in place just sandwich them with foam.
For SNES & N64 manuals buy cases with manual holding clips. For NEs games put the cart and manual in the black cart sleeve that used to come with the games and then put them in to the case.