This is a good site for info about raw feeding if you wanted to try it, its written by vet Lisa Pierson Feeding Your Cat** Know the Basi - it gives you all the info you need about cat nutrition and there are recipes too if you wanted to make your own.

You can also buy meat from the butcher (or supermarket) and add a supplement powder to make it complete and balanced, thats just another way of doing it. Mine have this sometimes, I get it from the Feline Future site Feline Future Cat Food Company - its also got a lot of good info about nutrition.

I don't know which site you've looked at with regard to buying ready prepared frozen raw meats - but this is the one I buy from Food4-Cats!, Just Food for Cats Nothing More! It is delivered frozen in insulated boxes for next day delivery. Nice wide choice of meats and they also do a taster box so you can try a variety of meats to see which yours like.