Hello and welcome from London.
About your IR filter, you will find that most IR negative films (and there are not so many left nowadays) recommend the type of red filter which is suitable for their film.
If you search online Maco, Rollei or Ilford's website, all make IR film and they would have published red filter recommendations.
I don't shoot IR myself so I cannot help further.
Also, you can use the APUG search or just post a new thread in the BW section ((there was a url link here which no longer exists)) and ask the question, all questions do get answered in a comprehensive manner.
I went to NYC last year, I loved it, though I thought that it was unsettling... I want to return to go to the Abyssinian church.
Best
Delphine