120y's are heavier at the front and dont have the nice 52/48 weight split like a 1200, they are therefore prone to understeer and basically not handle as good and yes they are damn UGLY

you should be able to get a 1200 coupe cheap enough but the utes are generally very expensive

you should pull everything apart, theres not much you can wreck by pulling things apart unless you cant put em back together but im sure you want to learn everything and know exactly what condition your cars in