I run with 80/120/150 and never deviate from those grits so adjusting the heads is not an issue. SCM makes some nice single/double head sanders that are in the $35k-ish range, new. There a decent used widebelts, including the one your referenced, that come up on the used market frequently.?
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Kerry Smith
Gotham Woodworks
www.gothamwoodworks.com
Kerryj_smith