Steels are CS70 or similar and 15N20. Plain carbon at eutectoid composition for max martensite,and similar with nickel in it. Nickel etches lighter. Extra manganese in CS70 makes it etch darker. CS70 and 15N20 behave similarly under the hammer and in heat treat so work well together. Owen's friend Mick Maxen has some pretty cool examples as well http://www.fireandiron.co.uk/mick-maxen/
Regarding handles, everyone has their style. I like the trad that Owen showed. I think Owen himself prefers big stuff – swords, seax, axes but too big a project for that type of filming. For ultimate kitchen ware, another acquaintance, Will Catchside, does some top class work: http://www.catchesidecutlery.com/
All three are international standard smiths from the UK.
Borax is used as a flux to prevent oxidation. Almost the same as you would use for silver soldering etc Difficult to have too much.
Liquid is Ferric Chloride as used for etching circuit boards but at lower concentration. A mild acid that brings out the detail, if a bit more slowly.
Edited By jaCK Hobson on 07/05/2015 08:52:11