For your kitties, definitely go with fish-free raw if you want to reduce the phosphorus content. Fish oil is no problem. I've only tried Primal's chicken necks, but found better sourcing later. Maya loves crunchy bones!
I started feeding my kitties NV Instinct medallions because once it's thawed, it's pretty soft and easy to mix into their wet food. I'd try mixing in a tiny bit if they like it first. Or, you could just use several bite-sized pieces of raw chicken thighs and sort of mince/chop it up to see which kitty would be more into eating raw, mixed with their canned food. Chicken thighs and heart will have high taurine content, so it's great if they eat it! Once you decide to go raw, I'd do it daily, and slowly increase the raw and decrease the wet. Also, during the transition, adding probiotics in their wet food could help lower the chance of any loose stools. Normally, I'd add a bit of warm water to the wet food, then probiotics, mix it up, and then put some bits of ground raw in, but use the wet food as a topper/gravy.
I no longer use the NVI only because I don't like veggies in their food. Cats cannot digest or metabolize plant matter anyway, so I use a local commercial brand right now. You could also check out local butcher shops or dog food stores for a raw grind that may be appropriate for cats as well, you'd need to read the ingredient label to find out if it requires supplements or organ meats, etc. I found one of my local butcher shop who feeds his dogs raw, so he had special grinds for pets that are a bit more affordable than pet-store priced raw.
Since your kitty Buddha had several blockages and a PU done, I'd also think about getting his urine pH levels checked every now and then when he's on raw just to be safe:
Hope other raw feeders can give you some feedback!