If you are struggling to find out how to set one up, I would question the ability to run one diligently and compliantly.
If not using an IFA is due to cost, a SASS could well not be suitable as generally quite expensive ongoing.
Finally, how so you know the SASS you may set up is the most appropriate for you?
Yes I am an IFA, but trying to be helpful so you don't get in a mess like some of my clients I have had to help after the event.