Chronos or RDG tools? Might be worth giving chester a ring? If you have access to a lathe then bushes are realy easy to make, thats what I do. This is a common question it seems, collets are v expensive and a brass bush is easy to make and grips tight. You don't need slitting saws, a cheaper razor saw by hand to slit is all you need. Maybe I should make some? Small detail... ball nosed slot drill can be driven vertically like a drill then horizontally because it has a tooth across the centre. Ball nosed end mills must approach the work horizontally because they dont have the across centre cutting surface. On hard stuf if driven vertically down they will skate around. Most retailers will sell "end mills" but they'e not, have a look, there should be one flute that goes across the centre of the tip of a slot mill. Niether as already said cut very well at the tip and it gets hot even with wood but slot drills do a little better. End mills nice for finishing contouring or that curved bevel effect thing that I cant remember the name of. For wood the single flute D type cutter works well and much easier to sharpen.