If you can find a groomer that will work on your cat, I'd seriously consider that route. At my current place, only the owner is certified to work on cats, so finding someone may be an issue depending on where you live. My cat hates all brushes and would hiss and swipe at me for daring to brush even his back, where there were no 'problems'. I mostly went to the groomer because while mine still manages to groom himself, he was getting... some issues that were better solved with a butt cut, let's say. He's got that 'lion puff' around his neck naturally, which is hard for him to lick regardless of age (lots of head whipping involved), so I get him a sany shave (butt & gut shaved) then I ask for him to be trimmed down all around and he winds up looking like a 'normal' short-hair cat... with his fluffy tail intact, because he grooms it and I love it. I was leaving him an inch of fur, but we've gone down to half an inch and he just looks sleeker/neater. (I'm also in the south, so it's not like it's freezing down here) Helping with furballs was another reason for a full groom.
When you say that she hisses and gives attitude about being put in the carrier, how is her demeanor with the vet/new people? I ask because while not as bad as yours, my cat runs away and puts up a mild fuss about getting into the carrier, cries for a few minutes in the car before pouting/ignoring me and then he's basically a timid, shy cat with other people, which makes him a good candidate to put up with grooming. I know some areas* will give the cat a sedation pill if they get anxious, but mine has never needed it. But that would be something you should discuss with your vet before grooming, to make sure it's ok for your cat.
* - I've been to 3 different grooming places. First stopped grooming cats, then I moved away from the second and now I'm on my third.