Best wireless accespoint for Pestest

Hi There
Me and my colleagues, are about to do a pentest job for a large enterprice in DK. One of the tasks is to hide a wireless accespoint inside the network.
Now we are looking for the smalleste and the best accespoint to use for the job.

We have allready some demands for it:
- Have to be small
- Have to be DHCP enabeld
- We have to be abel to change the MAC adresse on the device so that i looks like a internal pc/printer if they lookup the MAC adress.
- Long range as possible. We can be in 200-300 meters from the accespoint. (Maby another antenna will help ?)
- Maby it will be a good thing if it was running on the 5Ghz band ? (is it ?)
- We have to be able to hide it in some way (we dont know yet how we will do this)
- Have to run on WPA2
- MAC allow/deny list

So if anyone knows an accespoint ore some of these answers please feel free to write with links to rescourses and so on.
You can write directly to netcowboy_dk at hotmail.com

Best regards
Netcowboy