Here is a link to the infamous Janet & Binky food charts, which lists the amount of phosphorus in various canned foods: http://www.geocities.com/jmpeerson/CanFoodNew.html
I'm sure you know that something around 1% DM or lower is what you're looking for, which roughly translates to 240mg per 100 calories or less. The canned Wellness flavours that fit the bill are Turkey (200mg), Kitten (216mg), Chicken (219mg), and Beef & Chicken (226mg). I have no idea what the Wellness pouches come in at so can't comment on those.
If you want to go even lower, I recommend Innova EVO 95% Venison (146mg) and the 95% Beef (171mg). Felidae Chicken & Rice is also decent if you don't mind some grains (172mg). Some of the Precise flavours (Turkey, Chicken, Triple Delight, Deluxe Medley, and Mixed Grill) are all under 220mg. They also have grains, but small amounts since the overall carb content is quite low.
As far as getting him to eat raw, how have you introduced it? Will he eat a plain piece of cooked chicken breast? You might just have to go really really slowly, putting a pin-prick amount in with his regular food and then ever so gradually increasing the size over the course of several weeks.