Are you looking at adding your own pans or do you want them included.
IF you are looking at just a burner, as pictued above, you'll have to take into account where you intend using it & the availability of the required fuel. When(time of year) would you be using it?
Liquid fuel burners in many cases will win over gas burners. On the ease of use then gas will nearly always win over liquid fueled burners. You have multi fuel liquid burners. I have one, not certain of the model, but its made by the same company as the one pictured, which will burn almost any flammable liquid in a safe manner. Not cheap, but there is that option open for you.
The one major failing of gas fuel burners is the disposal of the canister after use & the fact that some may not allow you to seperate the canister from the burner once fitted.
If all round ease of use is the major requirment, I'd go with Tail End Charlie & say a aTrangia. You can always get the gas conversion kit at a later date, if you feel you have to.
Depends on what you want to do.
Just boiling water or heating dehydrated or packet stuff then any lightweight system will do, see the Caldera Stove. For more advanced cooking IMHO the Trangia 25-6UL. I personally like the non stick pans some people don't. I also have a Trangia Gas Burner a Trangia Multidisc and a Trangia Cooker Bag with mine. Obviously more money and weight than a basic water boiler. I like the Trangia set up for the fuel versatility and the ability to cook complex meals using ingredients pick up along the way.
It depends on the availability of the fuel, and thus on where you go. It also depends on the quantities of what you want to cook. Finally, it depends on the outdoor temperature. Multifuel stoves are great for trips in the third world, in really cold weather, and for larger quantities. But they are fiddly, heavy and expensive. Gas cannister stoves are cheap to buy, expensive to run, light (the solo ones), topple over quite easily (the solo ones), and the cannisters can be hard to get. There are two valve types: screw on (most of the world) and bayonet (Camping Gaz, France). Primus do a few Duo models for both types of valves. There are also adapters, but then you loose some of the weight advantage. Unless you use a heavier cannister stove with liquid feed gas stoves work less well at low temperatures. Finally, alcohol stoves like the Trangia. In Europe, the fuel is almost always very easy to get, cheap, and safe. But they burn slowly. That is fine for a solo stove, just about OK for two, but a pain for three or more. The Trangia 27 really is only a solo stove, and the Trangia 25 for 2, 3 max. Using the Trangia 25 for 3 only really works with either the gas or the multifuel burner. For a Trangia 27 used for one, I think either of them is unnecessary. The Clikstand and the Caldera Cone are less convenient ultralight alcohol stoves.
I got one of these from ebay for £16.98 including postage. The preheat tube and weight put it in a different league from most remote cannister stoves. I use it with a Gelert mini adapter for bayonet cartridges, which are much cheaper and lighter than the screw on sort. It's got good simmer control and so far I think it's the best stove I've used. I probably would have preferred a wider burner head but since I use narrow mug-type pots it's not really a problem.