Didn't read all posts. I bought a Tormach arbor. Super well made. Holder has no runout. Most saws do have runout.
3/4" straight shank means this can be used in just about any machine that has a 3/4" collet.
TTS™ Slitting Saw Arbor. For saws with 1 in. diameter arbor holes.
tormach.com
The TTS Saw Arbor: 1/2 in. is a slitting saw arbor is for saws with 0.5 in. diameter arbor holes.
tormach.com
Slitting saws themselves can be moderately expensive.
Grizzly sells cheap options starting under $10.
Grizzly Industrial, Inc. is a national retail and internet company providing a wide variety of high-quality woodworking and metalworking machinery, power tools, hand tools and accessories. By selling directly to end users we provide the best quality products at the best price to professionals...
www.grizzly.com
Harvey tool has high end carbide saws upwards of $600
www.harveytool.com