Hello Dan
If you can afford to in my opinion you should do both, preferbly the prochem training first,this will give you a very good understanding of practical carpet and upholstery cleaning with no exam at the end of the course.Then take the NCCA course which is mainly therory based with a multiple choice exam at the end,, you will already have had the excellent training that prochem provided, which will help a great deal .To get treatment risk insurance, you will find that you will need to be qualified in carpet and upholstrey cleaning ,in which passing the NCCA exam will provide you with
Cheers Mark