If you pay for shipping you can have the Wellness chicken I have >.< My cat ate it for weeks before turning her nose up at it.
My suggest would be to buy larger cans. I buy from Amazon Wellness's page and you can buy 12.5oz cans which is about 4.5oz per dollar opposed to the 3 oz cans which are over a dollar a can.
If you buy in bulk, it's much cheaper! https://www.amazon.com/gp/product/B000WFORH0/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
You don't want to feed them stuff that has grain or fish in it.
For a litter box try this. A friend recommended it to me and it's reviewed well. I'm still working on converting my cats to using them.