There are of course AlphaJets, M-346 Aeromacchi, F5 aircraft etc. In Poland was well designed TS-11 Iskra but that in my honest opinion cannot compete with L-39 Albatros. Because originally these are a bit two different types of jet aircraft no matter what features you will want to compare. Shape, aerodynamics is just one side where there are thousands of differences, also on-board systems from life support, engine control, navigation, landing support like ILS, support for maneuvering, sometimes systems to support the way you manage your attention and move it to the band of your sight directly the way you are heading on so HUD displays etc. Other thing is that different aircraft will be equipped with different jet engine, one or two. And it has to tightly correspond with aerodynamics and weight of a whole aircraft. Simply a lot of to optimize think and rethink and parameters that finally a pilot needs to be the best friend with!
From realistic point of view at my reach is this. I mean to fully learn to fly this.
I did not see this before
A video I discovered a year ago. If my search was quite covering all possibilities in the USA there are two places where you can learn to fly this aircraft
For me it is wonderful how popular is this Czech aircraft from 1968 around the world till today. Look after how many years thoughts of a few, of a team of engineers, designers, constructors survived with and till today in this class so few other projects can compete with.