There's no reason a good plastered wouldn't be able to cover that with a bonding cost and then another plaster cost Alternatively if you use smaller boards I would imagine plasterboard adhesive would hold it as the weight will be spread across smaller sections

Hi, we at Dual Designs are often designing kitchens up to the ceiling. It is usually because of the client requiring more cupboard space, along with making sure the design will suit their beautiful dream kitchen. We have designed cabinets up to the ceiling in large and small rooms, both work really well. It mainly comes down to person taste, some people would never leave a gap at the top, with the 'dust trap' word mentioned. Others who don't mind a gap would often say they can't reach high units and don't want to use a ladder. We always consider both the practical side along with the design and give an honest assessment to help our clients. I would think taking the cabinets up to the ceiling can work though a good designer will confirm this for you, so I hope that helps and good luck

They usually come with metal chains don't they? Therefore, if you were able to find a joist in the ceiling above, you can put a hook in to it to hang the chain from.

It may be worth speaking to the electrician if you're not as keen on swagging. I know they can run a "pipe" through the ceiling void with the cabling in to put extra outlets and then just drill a hole from underneath the ceiling for the light but that is dependant on the joist direction etc though. That may not be feasible for what you want to do but may be worth asking the question anyway! If not, choose hooks that blend in with the ceiling? It will be easier to assess position this way too as you can just get the electrician to hold each one up for assessment before fixing! A general rule is that lights should be 1/2 - 2/3 of the tables width and normally hung 30-36 inches above the table. Given the double height I'd probably just start the lowest pendant c40-46 inches but I'm not sure on your total ceiling height and even though it's a feature you want to make sure the table is sufficiently lit! It's probably worth drawing it out on paper