Buy the S4. I shoot a Scepter II with nitrous Cams that I put together. The Slayer is a 3-D, Hunting bow. As you get into Target Archery, 5 Spot, American Round and Field, you will understand why the Scepter 4. The Scepter 4 has a deflexed riser and the Slayer has a radical reflexed riser. A bow with a deflexed riser is much easier to shoot without torqueing the bow. As for a sight I would recommend a moveable sight from Sure-Loc, Toxonics or Copper John. Just make sure that the sight bar has enough travel to allow you to move it down enough for the longer distances involved in Field shooting and the American round. For a scope it gets harder. The diameter of the scope housing is different for what most 3-D shooters need as opposed to a Spot shooter. But a medium diameter scope housing will work for both. A Scope that takes a 1 3/8 diameter lens is what I shoot.
May All Of Your Arrows Find The Bulls Eye-MSMFSL
NRA Life Member
Scepter IV Elite w/Furious X Cams