What do you recommend?

Get ANR, if you can at all afford it.

What are the main features I should be looking for?

ANR and comfort. The latter can only be tried on your head. Make use of
money-back policies or a well-equipped pilot shop in your area.

Which manufacturers have the best reputations?

Bose is top and top dollar. Lightspeed offers excellent value. David
Clark tends to be overpriced when comparing the features you get. IMHO.

Any specific model
recommendations?

Lightspeed's 20XLc is a good "middle groudn" headset.

--
Thomas Borchert (EDDH)