You will need to use two seperate channels one for each access point.
Space the channels with at least five channels between them so that
they do not overlap ie channels 1-6, 2-7, 3-11 etc.

As far as using the same SSID that will work but you will have no way
of limiting how many clients connect to each access point. Some access
points such as Cisco support limiting the number of concurrent
associations and can better manage the avaliable bandwidth.

The one statement you did not make was what will the clients be doing?
The number of clients per access points is proportional to the demands
that each client is going to be placing on the access point. The
802.11G access points can sustain data throughput of about 15 to 20
mbits per second in real world use. The 54 mbit rate is an over the
air rate and is about as accurate as the MPG standards for vehicles.