The SenderoII is the new version. Rem. quit making the Sendero for a while, which brought about my Username.
The SenderoII stock is a little different in color/texture & it has a palm swell that the original stock did not have. Also, the fluted barrel on the old stainless version did not have black flutes like the new one. Also, some of the old Sendero's were blue & unfluted instead of stainless only as the new ones & some old ones were blue & fluted. So, the old one came in 3 versions.
The newer SenderoII versions have the new trigger, some of the SenderoII that were initially introduced had the old trigger.
Most of the time the Sendero is a cut above in the accuracy dept. & shoot great. I have heard that Rem. used select barrels for these, but I have no proof of that, but they sure shoot well.
Looks like you picked 3 very good bullets to try. My Wife used the 130Acc. in a 6.5X55 & it did very well on Antelope last fall.