no problem, good luck w/ the switch.
your cat w/ the urinary problems would definately benefit from a rawdiet! just remember, adding veggies will change the ph of the urine, so for your cat w/ the problems, he may do best on meat/bones only, since the ph of the urine directly influences the crystals. the canned food is a good start, cats NEED water & don't get nearly enough eating dry food only.
slowly add little bits of meat to the canned food he's eating. you can lightly sear the meats to get him interested at first also.
http://www.bravorawdiet.com is a fairly good company for buying rawpet foods. the meats are generally naturally raised & free range...& my cat absolutely loves the ground rabbit. it may be a good starting point & you won't really have to prepare anything. :) just remember, feeding whole foods (bones) is a great health benefit & will keep the teeth and gums clean and healthy!
good luck!