Thank you to everyone who has chipped in with help on this thread
Having now spoken to Hargreaves Lansdown, it appears they don't have an easy mechanism for doing monthly UFPLS so I think to get me started I'm just going to partially drawdown £20,000.
I will then set up a direct debit to send me £12,570 / 12 = £1,047.50 per month to use up the annual allowance. This will gradually erode the £15,000 remaining after the £5,000 tax free cash.
The £5,000 tax free cash will just be plonked in Active Savings over 5 years at around 5% currently. The balance remaining in drawdown earns the following interest at the moment if I just want to keep it really simple

I'm not bothered about the lost months of this tax year, I'm just looking to get started and will review again in a year or so as I grow into it all of this and get some experience.
Really, in summary, I'm doing this to syphon off the natural yield in my SIPP each year to use up my annual allowance in to me a simple and easy to understand way (hopefully!)
Appreciate many of you will already be doing this and that it probably seems like child's play but I haven't found it easy to decide what to . Mainly because it's that feeling of "I don't know what I don't know" !!!
Across 2 phone calls, HL have been very helpful and professional I must say
Thanks again all