You might find that your grandparents have got one in the attic anyway. There are many good ukulele makers all over the world. A guitar maker might make one for you, though a small guitar does not sound the same as a ukulele; the construction methods and materials are different. Members of the Ukulele Orchestra have obtained good ukuleles from: Marshall Stapleton, Pete Howlett and many other manufacturers including Hawaiian experts, but a relatively good one can be obtained from most music shops. The traditional wood for ukulele construction in Hawaii is Koa, though many ukuleles are made from other woods. In the UK, a reasonable uke can be found for around 25 UK pounds although one can find old collectable ukes or high quality instruments which cost thousands of pounds.
You can also listen to The Ukulele Orchestra of Great Britain's music on Apple Music or check out our YouTube channel for videos.