Users Complaining About Slows Applications. Help!

Question

All,
As many of you are familiar with, we have users who say the network/WAN stinks.  I'm in that situation, and I'm the network guy.  They say everything is slow.  I'm looking for a Solarwinds tool (or any tool for that matter) that I can install the client agent on the transmitting PC (it's in Mexico City) and the server agent on the receiving Server (it's in New York City), and have it FTP a 3-4MB file every hour or so.  Or, maybe not FTP, but any TCP traffic of a size I specify.

For example, if I say I want (every hour) to generate a TCP transaction that sends 300KB of data , the tool would fire it up at the specified time and, once completed, would report transaction time statistics in some sort of a log.

I just need an objective view of the performance so I don't blame everyone of expecting too much, if you know what I mean.  Can Solarwinds help with this?  If not, is there any other tool (maybe open source) that someone can think of which would help?