I used the steel rebar'y things. If the kit above is more expensive I'd stick to tried and true. Just make sure you go a foot or two past your structure, don't be tempted to "peg" the corner.
Yeah I use poly glue. I don't know the caberdeck but get what you mean RE: D4. This stuff foams up unlike any other glue I've used though.
On joist hangers I am pretty sure it is the 47x272. Wickes actually do a box of 50 which may work out cheaper.
Timber to Timber Standard Joist Hanger 47 x 272mm - Pack of 50 | Wickes.co.uk
Timber to Timber Standard Joist Hanger 47 x 272mm - Pack of 50www.wickes.co.uk
Ah where did you get the rebar from?.. Joist hangers for mine it says you want 112 hangers which seems like a lot...