Guidance while setup asterisk in a call centre

i have experience in configuring pbx in asterisk,never configured voip server in asterisk one of my client is a call centre
they are having 500 agents.i know vicidial, but client is not interested in vicidial.he had asked me following things.

[b]Which application ill be using. (suggest)

which crm ill be using. (suggest)

which database ill be using. (suggest)

VOIP server should be with predective dialer[/b] (suggest)

i have some days with me so that i can give him a presentation.plz guide me for this, and plz tell me what points should i keep in
my mind.