BFGarrett -
The McMaster tool you showed will have a flat tip, similar to a drill bit, where the flutes meet at a cutting point. You would have to measure it since they don't specify. A shallower cutting angle would be much easier to control than that bit. I think it was Randy that pointed me toward Bits & Bits.
This bit from them might be a good choice for you (especially if you rough first with a larger bit).
Every mill you use will have an effective end radius. If you use an easy to cut subplate such as MDF (or even aluminum, compared to Moly), even the dragging tip won't matter. Just set your feed to the smallest effective radius that you are using in your material on the taper. At some point the tip will drag, but at that size the cutter is strong enough to just go ahead and drag without breaking. You can also buy cutters with a specified tip radius. I never try to use the full feed rate with micro-sized cutters anyway, because I really want to just leave them alone and let them cut. If you back off the feed from the book value, you are more likely to get the part cut overnight without a tool breaking. Small cutters figure out how to break themselves without much help from you, so go conservative on the feed and depth of cut unless you have lots of cutters and want to babysit.
You may want to buy micro endmills and not worry about taper. Bits & Bits also offers straight endmills down to 0.005" from stock.
This page lists their stock sizes. Generally, the cutting portion will only be three times the diameter, so you'll need to choose sizes wisely to get the depth of cut you need. They also offer engravers and other cutters that may work well for you.
By the way (and it really is none of my business; I'm just curious), why Moly?
Regards,
- Just Gary