make you own. just buy some lengths of 4x2 and either some 1/2" ply or even chip board flooing, and rip off the toung and groove.
you could use the worktops given to you, but theyre not ideal surfaces as they are slippery, and fradgile, ie if mounting a vice etc. anyway lightly damaged worktops go for £50-60 per 3m length, so theyre not worth saving just for a workshop, where they will be impracticle anyway.

kitchen units seem a neat tidy idea, but theyre crap, and will fall apart as soon as you go to get the 1st spanner

dont worry about been a saddo! my workshops got oak beams, well thery were there alreadybut its, plasterd, painted, carpeted, i even have a sink, kettle and toaster, office chair and a hifi! and carpet in the pit as well!