hi,
cisco is certainly not the cheapest. but there is a solid tech support.
make a COMPLETE list of all features you want, eventhe most obvious simple ones, then see with the integrator if cosco can fill in. best ask to test that.
we have a call manager express. stable, but not that easy to manage and several simple things (you would expect from a pbx) cannot work or are not easy to use.
good luck
Shaoul