if you are into spherical pano, you can get a spherical pano head...a cheap but good one is the
nodalninja...or see if anyone on the forum has something similar to loan to try...mine's out on loan to someone so you can't borrow mine;p...
lens wise, I prefer something with minimal distortion...I don't like those distorted panos using wide angle lenses...I'ld rather shoot more shots to cover a wide angle with less distortion than using wider but less shots...of course, sometimes, like when subject is time sensitive than no choice...
as for stitching program, look in the link Megaweb quoted...me I do it by hand...