Read about shallowsumps with foam.
?where, how and who can supply me?
With foam

Not sure I would want foam in my sump!
Think about sludge etc
Heard of it in Fuel tanks, but not sumps.

isn't oil too thick to soak into the foam properly? and therefore to thick to come back out properly when needed?

Some of the Caterham shallow sumps utilise foam to prevent surge. However, there have been a few reports of the foam breaking up, blocking the oil pick up pipe strainer, and subsequently killing the engine

Not something I would personally choose to use in my sump...

There are other options such as baffles, drysump and accusumps to consider. Baffles being the cheaper option.

i was going to mention baffling the sump. If you're taking it off to shorten it, you may as well put some baffles in

Caterham have used foam in their 20XE and K Series engines cars. It's a risk if not changed regularly, certainly not something that will last the life of the engine. However, it's a cheap/simple solution that works well to prevent oil surge on shallow sumps.