The higher the impedance (Ohms) the less static gets through...but you need a more powerful amp to drive them.
The 32 version is meant for iPods really - I wouldn't really want to buy them tbh.
The 80s are meant to be amped, but they go to a reasonable level on portable devices and PCs without being amped.
The 250s need to be amped.
However, not much static gets through after 80ohms, so there's little difference in that sense between the 80s and 250s. If you look up reviews, most places say the 80s have a better bass and sound a little better than the 250s, but differences I'm sure will be minor.
Therefore for normal PC use, the 80s are probably the best to go for - although I would recommend a good soundcard such as the Essence STX with the headphone amp, or getting something like a Fiio E7.
So you know - I own a pair of the 80s, and they are amazing headphones.