  We present a carefully vetted equatorial ($\pm$ 30$^\circ$ Decl.) sample of
all known single (within 4'') mid M-dwarfs (M2.5V-M8.0V) extending out to 10
pc; their proximity and low masses make them ideal targets for planet searches.
For this sample of 58 stars, we provide V$_J$, R$_{KC}$, I$_{KC}$ photometry,
new low dispersion optical ($6000 - 9000$\AA) spectra from which uniform
spectral types are determined, multi-epoch H$\alpha$ equivalent widths, and
gravity sensitive $Na\,I$ indices. For 12 of these 58 stars, strict limits are
placed on the presence of stellar and sub-stellar companions, based on a
pioneering program described here that utilizes precise infrared radial
velocities and optical astrometric measurements in an effort to search for
Jupiter-mass, brown dwarf and stellar-mass companions. Our infrared radial
velocity precision using CSHELL at NASA's IRTF is $\sim$90 m s$^{-1}$ over
timescales from 13 days to 5 years. With our spectroscopic results the mean
companion masses that we rule out of existence are 1.5 M$_{JUP}$ or greater in
10 day orbital periods and 7 M$_{JUP}$ or greater in 100 day orbital periods.
We use these spectra to determine rotational velocities and absolute radial
velocities of these twelve stars. Our mean astrometric precision using RECONS
data from 0.9-m telescope at Cerro Tololo Inter-American Observatory is $\sim$3
milli-arcseconds over baselines ranging from 9 to 13 years. With our
astrometric results the mean companion masses that we rule out of existence are
greater than 11.5 M$_{JUP}$ with an orbital period of 4 years and greater than
7.5 M$_{JUP}$ with an orbital period of 8 years. Although we do not detect
companions around our sub-sample of 12 stars, we demonstrate that our two
techniques probe a regime that is commonly missed in other companion searches
of late type stars.
