These are to be fitted in a work surface and a kitchen unit.

I want to do the job right such that if inspected there won't be any
issues later.

I've read:
http://wiki.diyfaq.org.uk/index.php?...as_fitting_FAQ
but its a bit quiet in certain areas though gives a good indication of
determining leak-rate.

Where possible I was going to use end-feed fittings, though the only
demountable fittings I can get are of the compression variety. In the
past I have been able to source gas union joints. Is this OK to use
compression joints if at the back of the units and under the work
surface? Will they be deemed as accessible?

I understand there ought to be a means of isolating the hob and oven.
Is it acceptable for this to be a single valve for both appliances.
There are "Fan Key Gas Cock"s and "Isolating Gas Ball Valve. Which
should I use? I can get the Fan Key Gas Cock in a capillary form, but
of course that will require dismantling and reassembly with new grease.
I don't have the proper grease at hand, will alternatives be OK?

I'd appreciate any guidance.