Are CoA and CoAS the same thing in a compound?
To understand the nomenclature here it is very helpful to think about how Coenzyme A works. It has a thiol group (-SH) which can form a thioester bond to an acyl group. 

So the sulphur in "CoA-S-R" is part of the CoA, and in "CoA-R" the sulfur is just not explicitly named. Those two mean exactly the same thing: Coenzyme A linked to R via a thioester on the thiol group.

One specific variant that is very important in biology is acetyl CoA. The chemical formula you mentioned (CH3C(=O)CoA) is acetyl CoA, and here the same as above applies and the sulphur is explicitly mentioned in the second one and implied in the first one.