You do not need to get your own solicitor to do this.
One small point: the "switcher" product may involve signing documents in front of a solicitor. The NIB "switcher" team will pay a solicitor for this, but it really is not worth his while. (I have done a few where clients of mine were using the 'switcher' type product and despite the blurb that I am 'only required to witness signatures' I have found myself effectively drawn into advising for free, opening a file etc. for something like €120).
If you like your solicitors and decide not to use them in this case, it would be polite not to go to them to get the 'switcher' documents witnessed either.