Vaejovis spinigeris sells occasionally on the wild caught list of GoldenPhoenixExotica.com, more commonly. I don't have too much info on them though. Invertepet.com also offers it on the scorpions list. The species for sale are from the deserts of Arizona. Species requirements call for sand substrate, a hide, 85-90 Fahrenheit temps and 60% humidity. They grow to an average of 2-2.5 inches in length.
Kind of strange to call them 'Texas Gold' as they are not found in Texas. The type locality for the original identification was labeled "Texas"; but that was in 1863...they have not been found there since. The do howeve occur in Arizona, parts of southern California and parts of western new Mexico. They can also be found in parts of northern Mexico.
I think in this case it all depends on the size...as far as visual appearance relates to a quick ID between the two species (V.coahuilae and V.spinigerus) with out knowing the adult size I have seen both of these species look the same in color and pattern depending on the lighting.
I would say that if your scorpions are in the 3-4cm range then most likely they are V.coahuilae. If they are on the average larger that this and in the 4-6cm range then they are most likely V.spinigerus...this is without taking any other anatomical factors into consideration.
Behavioral differences I have noticed are that V.coahuilae are incredibly fast and dart around with amazing speed. V.spinigerus is capable of this but does not, in general, dart around like V.coahuilae.