you will be fine with any of the "standard" studio headphones like e.g. sennys hd280, akg 240/271 or beyer dt770

some headphones have a high impedance of 600 ohms, but you can use 'em as well, pretty much any headphone amp is able to handle between 25 and 600, the high impedance cans are better if you want to run dozens of them on your headphone amp.

you should pay more attention (IMHO) to which sound / criteria you want / need, e.g. isolation, comfy wear, and so on...

I would recommend the akg 240s..
i first ordered the df version but the impedence of 600 ohm was so high i could barely hear them even through the high output headphone spec on my emu1820m...

So i got the 240s version with 55 ohms, nice and loud...
Sounds very good for the money, comfortable...

I haven't done many comparisons with other headphones tho...
D

oh yeah, i forgot to mention that the lower impedance cans are usually louder (so maybee better for you) the sennys hd25 as 70ohm version will pretty much perforate your eardrums...

but i like the sennys hd280 and akg 240/271 as well most...

So.... If I understand correctly better low impedance for the final monitoring, but high for the recording in series but how would I "headphone" the band (say 4 members) into the one headphone socket?

Headphone amp for example :
4-Channel headphone distribution amplifier , Behringer HA 4400.
Also other pieces, better quality etc.

cheers

:)

http://www.rane.com/note100.html
also has an excellent chart of popular headphone impedances and SPLs

I think 50 to 25 ohms to too low for most op-amp based HP amps
A passive distribution box off a small power amp can do this easily even with 6 or 8 multiples

http://www.rane.com/note128.html
an HP amp is still an amp and the problems could be even worse for op-amps.
Op-amps have less current capability and as you come down to 50 and 25 ohms the problems grow.
You get both voltage clipping and current limiting.

Try out some Ultrasones as well.

I am VERY happy with my 550's and 2000's.