I think it depends on what you want to achieve, a daily 6 pot doesn't come cheap, thus maybe a 4 cyl might be better for the purposes of work and back,
As for 325i, if fuel consumption is not an issue, why not a 330i whilst you at it? Power levels in cars have changed over the years, I'd say get a 170kw motor with adequate torque (300nm) and have peace of mind, I'm yet to find a 330i owner with buyers remorse.
I have a 325ci - extremely fun car to drive, puts a smile on my face, but sometimes I just feel I would do with that extra bit of power. 325s have high reviving motors.....and one major con for me is the 5 speed gearbox, you can actually feel the car needs a 6 gear.