Found time to dowel joint (Joint Genie Pro) & biscuit joint (Screwfix
cheapy) some cupboards in PAR Oak with white polypropylene back
panels.

For the cupboards I notice the oak is cupped slightly - enough that it
will need clamping as the glue sets. For the end panels I will also
need some form of clamping. The widest cupboard needs an 800mm span.

Is a 36" sash clamp the right tool?
There is Ebay 190040939713 (alloy) & Ebay 190040939346 (T-bar) for £20
& £23/pair.