Hello, I am a solicitor with 20 years experience. I will try to help you with this.
No you can not face imprisonment for this offence. The maximum ban is 56 days at your level of speeding it is almost inevitable that your ban will be close to that level. The fine will be at level B which currently has a £1,000 limit. You will also have to pay a contribution to prosecution costs. Being represented by a solicitor will increase your chances of keeping the ban low or even if very lucky avoiding it.