The dashboard port is great if you need high-level debugging (eg, is your arm at the end of its travel). By the sound of it, some kinda of serial stream from the RC is the best way for you to go.
As for the PC side, it depends on how you want to use it. I've never used Labview, but for just real-time graphs, it may not be necessary. I'd be willing to bet that there is OSS that can take a stream. (Under unix, you can probably do some FIFO/piping magic so that you can point software to it and the software will read it like an endless file.
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I've never had a serious need for this, so I've haven't done the research. I do know, though, that SourceForge has a project for practically everything. Do some digging on there.