I've had labs all my life, along with other breeds (and non-breeds!)
I find the black labs are usually the easiest to train, then the yellow, and lastly the chocolates.
I currently have two chocolate dogs aged 8 bred from a working mum and show dog. One has epilepsy and needs expensive meds and is just starting with arthritis. The other is in rude health.
They need to be watched for weight gain, and will steal food if given the chance when no one is around. Young dogs need heaps of attention and will tend to be destructive if left and underexercised. Mine are large dogs and do take up a lot of room in the house, they also tend to get muddy in wet weather, whereas the lurcher is spotless.
They do love to please their owners and enjoy a job to do. One of ours loves carrying the firewood home for us and they love retrieving things. Ours swim almost daily, but take ages to dry off.
With cats they need to be trained not to chase them, a young energetic dog might not be the best mix and something older and calmer would be easier to avoid confrontations depending on the dogs and cats character. Your cat will have its nose pushed out and be unhappy at sharing initially. You definitely a safe place for the cat to eat or the lab will scoff it. We use a stairgate to keep a room dog free; but microchip feeders are another option and feeding the cat at height. Mine live with six cats quite happily. (the cats are the boss)
Hoovering is a definite issue, and probably explains why I have a hoover fettish; currently a Bosch Athlet, Miele at and dog, and Vax Air, which all get used. I also have a good carpet cleaner. Be prepared to wash greasy marks from doors and walls where they rub against!
Saying all that, I love them dearly, they are great dogs!