'Mark One Eyeball' ... Spot on, no reason you cannot make your own!
I make things on a daily basis, save my employer a fortune.
You said 'Hydrolic block splitter'. Make a frame, and mount a bottle jack, presto Hydraulic splitter. A bit of effort, you do not need a engine. Now, what are you splitting... ... Logs? ...Slabs? ...Blocks?
Depending on what you want to split, the actual cutting edge. Mild steel will be OK, 3/8" for logs, 1/2" slabs, maybe 1/2" maybe a bit heavier for concrete blocks. Steel stockest will supply whatever you need, if you can weld it together yourself so much the better, if not there must be a fabricator/welder around Newcastle to help you out.
Let us know how you get on. John.