Green Patio Cylinders and Red Propane Cylinders = SAME gas.
We KNOW 13kg Patio Gas for the first time user is going to be hard to find this year. Simply because 2020 had such massive demand for them. They haven't been used up, so they're not back in the system for you to buy.
Appliances tend to arrive with the CLIP ON regulator for patio gas (the green one) but with a change of regulator to a standard 37mb propane screw in then it's possible to use the red propane for your bbq*. The regulators are readily available online quite cheaply but always buy from a reputable source.
Click on the link below to go to Calor's online help page about all gas bottles for BBQ's.
The 5kg Patio cylinder can be a great choice for anyone with 3 burners of fewer, or for your table top heater. It's likely these will be the route that many first time users will need to take simply due to availability for first time buyers of the larger cylinders.
* But do your research first, if you choose to change your regulator be aware that you may invalidate any insurance or warranties on your equipment and always check for any safety restrictions provided by your manufacturer.