Hi Markimark, welcome to the forum.
Perhaps you could tell us a bit more about your Dad and his Parkinsons problems.
There are lots of tips about sleeping comfortably, depending on the difficulties faced eg silky sheets to enable easier turning over...bed sticks to make turning, sitting up etc easier.
The link you have attached seems to show very expensive beds which would not necessarily help.
A visit from Social Services is often useful in identifying the best aids and there may be help in funding or loan of equipment.
Don't rush into expensive purchases without a bit more research.