Purchase advice V70, S60 or S80

Hello, I am an absolute Volvo Newbie and would like to ask a few questions about the Volvo models. Can you please explain to me in which classes the models S60 and S80 are to be classified (size)? S60 = 5 Series, A6, E-Class S80 = 7 Series, A8, S-Class or was that wrong? I am looking for a successor for my A6 2.8 Quattro automatic 193PS suction cup I tend to a model from 2003 with the 209 hp 2.5T engine. Is the engine recommended? Or should you choose the 2.4T from 2001 or even the 2.0T also in Bet I have set my price limit to approx.13K€. I often ride short distance <20Km but he should also have enough power to drive fully loaded with 4 people + ski box in ski holidays. And sometimes to pull a 1500KG trailer. Annual speed approx.: 15Tkm I would again tend to an AWD because 2 times a year ski holidays and occasionally trailer rides. Or can you do without it? In the gearbox my choice would tend to hand-operated because the automatic would swallow too much power t. How good (maintainable) are the machines from Volvo? Own development or purchased? I tend to the V70 but the prices for the S60/S80 are also very interesting. Just the question if you can ride with 4 adults + luggage comfortably 800Km on ski holidays? I think the V50 falls out because of the size even if I like it visually very much.