I try and be brief. I was told by police to expect a second interview, but it never happened. After about 9 months, I received the charges by post, with no prior warning. They had not been through all the devices and weren't going to bother, as they had already found enough evidence to prosecute.
Spoke to LFF on the phone, did the whole online course, but didn't pay for the face to face one. I don't honestly think it matters which one you do, all the judge will want to know is that you did something to address your issues. Do it if you feel it will help you, on a personal basis, to talk to someone. I also did some counselling and spoke to my GP.
I hired a local solicitor, not a specialist. There were two reasons for that. One is that I was pleading guilty, so it doesn't really matter so much. If I was pleading not guilty, then I would have definately considered a specialist. The punishments if you plead not guilty and it doesn't work are going to be much worse. Plead guilty at the mags court and you get a reduced sentence straight away.
Second, the local solicitor and barrister know the judges in their area and the CPS proescutors. A specialist from elsewhere may not.
The barrister told me two things. First, the judges see so many indecent images cases these days, they know the score. A specialist solicitor won't tell them anything they don't already know. Second, what the judge wants to know, is not what you did, or even why you did it, but what are you going to do now to help yourself change. If you are going to plead guilty, then that's where you should focus all your attention. I wrote a letter to the judge setting out a bit of background on my mental health problems, etc, admited responsibility, showed remorse, then all the stuff I'd done, since arrest, like LFF, counselling, anti depressants etc, to get help.
I would strongly recommend that approach. Write a letter, then show it to the solicitor first. Give the barrister as much detail about your life history as you can, so they have something to work with. They will pick the best stuff out, to present to the court. Good luck!