Justin, the Bosch steel guides are best for rough construction and you can buy any size by itself. The selection of sizes available is limited. Many people prefer the brass PC style for a couple of reasons. Brass will not chip a carbide router bit if they get knocked together. There are more sizes available. You can also use the 3 largest PC brand steel guide bushings which are 1-1/4", 1-3/8" and 1-1/2". The more sizes of guide bushings you have the more offsets you can use. I prefer using the set of brass PC style guide bushings from Woodcraft. They all have 1/4" height where other brands use both 1/4" for the small diameters and 1/2" for the larger sizes. This means you must have both 1/4" and 1/2" material to build your templates from. All my templates are made from 1/4" Masonite. The Lee Valley guide bushings are all 1/4" heights too.
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