Cutting v Milling holes

[Randino]

I'm new to shopbot and CNC machining.
My project has several different diameter holes (3/16, 5/32, & 7/32). I'm cutting the profile with a 1/8" end mill inserted in a 1/4" ER 25 collet. Is it better to drill the holes or use the 1/8" end mill? If I drill, what drill bit do I use? How do I chuck them, I hate to purchase a whole set of collets. I can't seem to find 1/4" shank drill bits in the size I need. Do they make a drill chuck I can use instead of, or in addition to the ER 25 collet....
I'm using the PRS Alpha with a variable speed spindle.

[garyc]

Randy...
I would use a 1/8" endmill, inside profile with spiral ramp to cut the hole sizes that you list. The lowest RPM for the spindle may be higher than the drill bits are rated for.

[srwtlc]

If you want a little more strength than the 1/8" bit, you can get 5/32 from Centurion.

Here's their upshear ones...

http://www.centuriontools.com/router_bits_toolcase/centurion_tools_showcase.html?splashPG=y&__max=6&pageID=1&cart=13250332996665332&id1=374&id2=538&id3=539&id4=773&startat=1&--woSECTIONSdatarq=773&--SECTIONSword=ww