Honda B18C engine

[deezee]

I know you say "Custom Bellhousing" I've had a look at some people who can machine bespoke parts up and they are listing one offs like that for £400 +

Well 400 quid is good money towards a normal engine thats not going to be a problem. If you want a jap engine, I'd recommend a 4AGE thats got loads of support in terms of tuning and parts for kit cars, or a SR20DE/T which many of the aussie guys use.