Option B looks more like what I would be thinking and there is another plus your not mentioning, your monthly disposable income will increase by the mortgage amount
Yes indeed Cervelo , and maybe I could treat myself to a Cervelo S5 (I'm a keen cyclist but not sure I could justify that price!).
The other "problem" is what to do with the extra disposable income each month , maybe the guy that said more money more problems had a very valid point. I do really appreciate how lucky we are to be in this position especially coming from a low income household as a child and still relatively speaking low income household. My hobbies are mostly cheap or free, walking ,cycling ,hiking , so I will struggle (for want of a better phrase) to use any more than necessary. With that in mind I will probably transfer the same amount out to some form of savings account be it for kids future / to cover some emergencies that are unforeseen etc.