With an $800 budget and previous experience with a Ruger 9mm, I would suggest a Glock 26 with pearce ext. Use the money left over for your preference in nite sites, decent holster like sidearmor, extra magazines, more practice ammo. At realistic ccw ranges ~7yards max, the shorter site radius, barrel length velocity loss, and caliber are nonissues. Any +P JHP from the four premium brands will more than suffice and if things really get bad, the 26 will accept spare G17/19 17 round mags.
One thing to keep in mind. Since this will be a part time carry weapon and you are in Texas, the gun will be subject to sweat. The sig finish is not known for its durability unless you get a stainless steel model. Showing cosmetic scratches and being rust prone is usually the #1 complaint of sig owners. If you're the obsessive cleaning type, then its not a problem.
One thing to keep in mind. Since this will be a part time carry weapon and you are in Texas, the gun will be subject to sweat. The sig finish is not known for its durability unless you get a stainless steel model. Showing cosmetic scratches and being rust prone is usually the #1 complaint of sig owners. If you're the obsessive cleaning type, then its not a problem.