PRSI Contributions if self employed

I lost my job 3 months ago as company closed down. I am currently on JSB and looking for new roles here and away. There may be a possibility of getting a 9 month contract here, but I would need to register as self employed. I am aware that the S class PRSI contributions to not entitle you to JSB. Is there an option to pay extra PRSI contributions as a self employed person so that you can avail of JSB at the end of the contract? Also, would my previous contributions as an employee (18 years) be taken into account? While I would rather continue to live here I'm not sure if my best option is to continue to look for a permanent role in the UK. Thanks.

There is no option for the self-employed to pay a higher Prsi contribution to improve their benefits.
The applicable year, when applying for Prsi based benefits, is two years before the application year, so your Class A payments, and JSB credits, will continue to have some effect for that time.
If you do go to the UK, see if you can continue to pay voluntary Prsi contributions here, as they will count towards your retirement pension. You may be able to receive a pension from both Ireland and UK when the time comes.
(No promises that the rules won't change).

Thanks for the information, I'll look into paying PRSI here if a job offer arises in the UK.