I know that on the standard pump the regulator has it's own spot to mount on the pump and the mounting bracket is slightly different. Also the standard pump isn't as long when mounted so it fits in a tighter area. There used to be a graph showing performance of each pump but I can't find it now. I don't think there is much of a performance difference between the two.

 

Star is very good quality. Sportsman pump is cheaper, Standard is for use with power adders and such. I like the regulator mounting right at the pump. Does not pull in outside air into the engine. I had one truck pull engine that had 1/2" of oily dirt in bottom of pan, that had the regulator on valve cover. put regulator at pump and next time I saw it, nothing foreign in the bottom of the pan.

 

You can still put the regulator on the pump but it's a little higher cost and not as compact.

 

Shoot them a message through the site. Tony is good to work with and very responsive.