I want to share my own experience of finding the right instrument. It is a very personal point of view but I want to give an insight in what I found is essential to understand.
Buying a uke is a very tough journey. You can find hundreds of instruments that somehow do what you want or what you like. But there will be one combination that triggers you all-time. As a beginner in something we tend to buy a cheap instrument which is a bad step. Cheap instruments have always something the player needs to correct while playing. It’s better to go to the lower end of the high prized instruments. So in Ukulele dimensions. Better buy one for 350 than for 30 or 60. When you made your first successful steps you can take a cheap one because your hands and fingers will correct the little errors of the instrument intuitively.
But what is more important to the instrument is the wood. The tonal abilities that different types of wood offer. To share some personal experiences. Spruce is very commonly used for singer songwriters cause of it’s easy attack. Soft striking the strings results in immediate resonance of the wood. Clear tone, ringing, high notes as low notes are presented easily. Loud resonance. Mahogany which is often said to be a good wood is different. You have to strike the strings harder, the tone will be very equal whatever you do, but it always will be round in the middle frequencies and low in the high frequencies. So for a solo instrument for playing jazz it could be interesting playing the lower range of the uke up to the seventh fret but everything above that will be hard to hear played live. walnut is similar warm like mahogany but the higher notes are clearer to hear and the overall aspect is very harmonic. ebony for me is not a good material for the Ukulele cause it is not taking the light strikes of the strings. You have to play with a harder approach to get nice results and the tone is very thin somehow.
At the end I myself think Koa or European Amaze is a wood that is the right one for a Ukulele because it is giving a very round overall nice covering of your work on the strings. But that is my personal impression after owning and playing some Ukes.
In general I would go for a spruce top instrument. Whatever the body is built of. As long as the top is spruce it will represent what you do on the strings in a nice way.
Another aspect is the kinetic effect the wood has if you touch it. The haptic aspect is important. Do your hands love to be in contact with the instrument. Aside that you shoud watch if a high gloss finish is the right thing for you or a natural finsh or even an oiled instrument.
Does the neck supports your left hand or is there something different or even disturbing. Is your right hand on the right spot. Means is the shape of the Uke supporting your positioning of the arm of the right hand. If you are used to put your pinky finger on the body of an instrument it could be difficult on a cutaway body to do so.
And last but not least. A pickup for amplifying or no. I would say no and yes. Plug the Ukulele in an amp and see what happens to the result of you playing a tune you know very well. You will be astonished. Most Ukulele artists are microphoning the Uke because of the percussive work they do with their right hand.
And the last important thing I had to learn buying and playing a Ukulele is the following. Do I want to hear my ideas played on a Ukulele. It is not unimportant that the instrument you play something on could maybe not be the right instrument for what you want to do. I myself have a harp for these situations and a piano for other situations and a bass for even other situations and I use a tenor guitar for other situations, a tenor ukulele for other situations and a soprano Ukulele to test if something I try to do on my concert Ukulele is a mind bug or really an issue.
After all buying the right instrument is a journey that at least has one aspect you’ll find out after you play your instrument for while. The strings. Nick wrote some interesting articles about that on his blog and even published some youtube videos which are good to view.
So as a fazit I can say: You’ll not buy the first Ukulele, you’ll buy some of them to find the one that suits most of your needs. I doubt that it will be possible to have one that suits all situations you’ll find yourself playing music.