I bought my mast parts from this place -
http://www.antennapartsoutlet.com/ - guy wire, mast clamp, roof bracket. I just picked that store based on what they have and price - they offer a fair price for the parts and for shipping. The rest came from Home Depot - the mast is a chain link fence top rail, and the rest is standard hardware. Guy wire is just 1/8" or 3/16" steel cable - you can get that at the hardware store too, if you choose to. Look in the section with rope. RG-6 cables from Amazon.