36 foot boat, 3.5 tonnes, anchor type TBA.

Intention is to typically anchor in 4-5 meters.

Seems like this would be ideal - any issues with this? I wasn't sure about the breaking load - 750KG seems like not a lot for a marine application!

www.bunnings.com.au/pinnacle-8mm-5-16-x-12m-stainless-steel-chain_p0358141

Forget Bunnings it's **** go Suppliers of OMC G43 Anchor Chain way stronger than standard anchor chain and fantastic price.
ozzimarine.com.au/

For a 36 footer I would use 12m of 10mm stainless. Check what your winch needs if fitted.

As Ramona has mentioned.
My first consideration is, "Does it fit my winch?"

For me the first step was to find a quality supplier that backed their product. Mine is 39ft and 11ton fully loaded. Ended up getting 80 metres 8mm which has been used a few times in deep anchorage and / or heavy weather. Only downside is the weight in the bow drops the bow waterline a little unless in cruising mode and weight is stored aft. There's a great supplier in Kirrawee NSW that'll give a good price if you pick it up.