Are you seriously a Software Engineer? They provide a well documented straight forward API with sample code and programs in umteen languages... Pretty responsive support forum and deliver 25ms precision data consistently. You really need to roll your sleeves up and dig in. Real time is all in memory and you can do a symbol spin (In your terms read the cached symbol table) at any time. http://nxcoreapi.com/doc/ Love em or hate em... These guys do data right and respond to any reported inconsistency. What they deliver requires a coder so you should be in heaven.
The NxCore data is compressed 20:1 so yes I agree that the raw data would be quite large. The equity feed that I was talking about with this scripting is only ~2gb per day so that's ~40gb uncompressed which still is well within the realm of a SSD. I'm using a 64gb SSD for this data server's OS (Server 2008 R2 Enterprise, 64-bit) and primary tape drive. Haven't had an issue yet.