Why dont people do a build like this link I found in youtube?
"http://www.youtube.com/watch?v=F1vNveXSprc&feature=channel_page"]http://www.youtube.com/watch?v=F1vNveXSprc&feature=channel_page

I want to build this but the motors I am looking at Will I be able to do this with this size of motors?
Motor Choice #1
Voltage (V) 6.3
Current (A) 1.5
Res. (Ω) 4.2
H.T (N.cm) 140
Length (mm) 76= (2.992120") inches
Rotor Inetia (g.cm2) 440
Weight (kg) 1.1= (2.425085lbs)
For some reason in the PDF it doesn't give me holding torque and Detent Torque...But on theses but some of the smallers motors do show those Ill list those in a sec.
This is the other one I am looking at:

Motor #2 Step Angle =1.8 Motor
Ambient Temp. -25~+40Cº
Insulation Class =B
Voltage (V) 4.1
Current (A) 2.3
Res. (Ω) 1.8
Induct (mh) 6.5
H.T (N.cm) 140
Length (mm) 76=(2.992120")
Wire Diagram= C
Rotor Inetia (g.cm2) 230
Weight (kg) 1= (2.204623 pounds)
Theses also 58.2(mm) X 58.2(mm)= (2.291334")
Using the YouTube link and the specs of the first option for the steppers Am I going to be able to do Aluminum stuff or just wood on this CNC?