Rent for proof of residency

Hello,
I am a dentist from EU and I have a job offer from a dental clinic in UK.
I need a proof of residency to open a bank account and to get a NINo, but for the first 6 months of my employment I will be leaving outside of UK for training provided by the company.
So, I would like to rent a low cost place, just in order to have and maintain the proof of residency during my training time.
Any advice? Or offer?