The problem is your phrase "near real-time". That's pretty vague and fraught with problems. Windows/MAC/Sun/Linux platforms are not real-time operating systems which means timimg is not deterministic - can't rely on software alone to provide known response times. There is a LabVIEW Real-Time module that downloads your VI to a board with a real-time OS.
I'm not sure what you mean about "hack the LabVIEW VI source code". LabVIEW comes with a large number of functions you need for streaming data, data manipulation, and inter-app communication such as ActiveX. There are numerous shipping examples and others available
here on a vari
ety of subjects that you mention. If you can come up with some specifics, someone here can provide more help.