Pay the extra money. The OMC manual is best. The Selocs I have used
before, but I always find the info is sparse or missing.

A good sturdy vise, attached to a good sturdy work bench and two sheets
of 3/4" plywood laminated together works well. And you would need a
short leg attached to the plywood to support the other end of the wood
that is not in the vise. But the stand you made idea is great,
especially if you have it on casters (wheels) and it's portable.

Have fun with it :-)