For humidity & temperature I already have that on my moisture meter by Testo, but if you are looking for an anemometer, Kestrel, Vane, Extech, Testo and Fluke are well known brands - the main thing is to read the specs & make sure they meet their needs. I would recommend one that does data logging and has the vane attachment which is one method for measuring air-flow
For flow equipment are you talking about Duct Testers, Blower Doors or a Balometer?
Duct & Blower doors - there are two main choices, Retrotec & Minneapolis. Personally they are both great products, but Retrotec met my needs better.
Balometer - sorry I can't help you on that one but if you shoot me an email or call me - I can get you the number to my supplier who can actually answer the pros & cons on those systems