I need film advice...

[Jim]

Hi! I have my first "real" assignment coming up soon, a group of headshots for a local ballet company.  They want the photos in black and white, which I enjoy doing.  But I'd like some advice as to what film to use... I will probably be using my trusty Super Program, and will be using either a Pentax M Series 135mm/3.5 lens I just purchased on ebay, or if it hasn't arrived by the appointed time, my Vivitar 70-210/4.5 zoom.  I will probably only be using my Sunpak Auto 266D flash for lighting.  Shall I use Tri-X, or is there something else you would recommend?  I'm all ears (in a manner of speaking). Jim