Where can I get data on lie detection and brain activity? Are there databases or data sets that contain metrics about lie detection?

The data would include variables such as:


Did the subject lie? (0 or 1 variable)
Brain activity measures (fMRI, EEG) when subject was given question. 


For example, was the hippocampus hyperactive when the subject was probed about a question? (Could be a discrete or continuous variable)


Metrics of the rest of the body


For example: Average heart rate, blood pressure level, level of various hormones, facial expressions, body posture, etc.


Any other metrics to describe people (remains to be seen if some of these variables would be useful): socio-economic status, age, race, gender, political affiliation, relgious affiliation, etc.


Does data involving, at least, points 1, 2, 3, exist? Point 4 would be a luxury, I suppose.
You might have trouble finding raw data but there have been plenty of studies looking at the neurological and physiological activity associated with deception, which may contain answers to your question:

A few examples:
Ganis et al used fMRI and found that both types of lies (rehearsed &amp; spontaneous) elicited more activation than telling the truth in anterior prefrontal cortices (bilaterally), the parahippocampal gyrus (bilaterally), the right precuneus, and the left cerebellum. At least in part, distinct neural networks support different types of deception.

Thackray &amp; Orne published a pretty thorough comparison of lie detection methods.

Bradley &amp; Janisse looked at threat and deception but discuss physiological response in depth. 

Abe et al used PET scans to argue that we have distinct neural pathways for deception.

Additionally Sip et al discuss the efficacy of deception detection and studies summarising that 


  The problems
  that bedevilled the old technology have not
  been eliminated by the new


References: 

Ganis, G., Kosslyn, S. M., Stose, S., Thompson, W. L., &amp; Yurgelun-Todd, D. A. (2003). Neural correlates of different types of deception: an fMRI investigation. Cerebral cortex, 13(8), 830-836.

Thackray, R. I., &amp; Orne, M. T. (1968). A COMPARISON OF PHYSIOLOGICAL INDICES IN DETECTION OE DECEPTION. Psychophysiology, 4(3), 329-339.

Bradley, M. T., &amp; Janisse, M. P. (1981). Accuracy demonstrations, threat, and the detection of deception: Cardiovascular, electrodermal, and pupillary measures. Psychophysiology, 18(3), 307-315.

Abe, N., Suzuki, M., Mori, E., Itoh, M., &amp; Fujii, T. (2007). Deceiving others: distinct neural responses of the prefrontal cortex and amygdala in simple fabrication and deception with social interactions. Journal of Cognitive Neuroscience, 19(2), 287-295.

Sip, K. E., Roepstorff, A., McGregor, W., &amp; Frith, C. D. (2008). Detecting deception: the scope and limits. Trends in cognitive sciences, 12(2), 48-53.