To the best of my knowledge a solicitor won''t be able to do anything that you can. In this you are better off doing it yourself as it will cost nothing. Save the money for representation.
The normal process is that the other party would apply for the SIO. The court would examine this and send the application back to the applicant with a notice of proceedings and a list of questions.
The applicant then needs to serve you with the notice of proceedings, questionnaire and copy of the application.
The normal court turnaround for something like that has been about 2-3 weeks in my dealings with them.
I wouldn''t expect Cafcass to be able to help you where the court can''t. Cafcass will undoubtedly be involved in a LTR application but I don''t think they will be able to tell you anything that the court can''t.
I once asked Cafcass what date we were next in court, they told me they couldn''t disclose that information and to check my order. I was only speaking to the call centre there though so you might have a different experience.