The real question shouldn't be "Which make?", so much as "What I am going to use it for?" because these decisions should always be based on purpose and need.
For example, if you're planning just to take basic portraits then even the cheap and cheerful ones sold on fleabay will work - at least for a while, but the learning process can be very frustrating because the equipment is too limited and too inconsistent - and if, at the other end of the scale, you need to photography white ice cream against a white background you'll need absolutely perfect colour temperature and flash energy consistency, and only Profoto and Bron will do, or at least only those makes will make life easy for you.
If your needs are less demanding but you still need to grow your kit over time and add a range of good quality light shapers, then any of the established brands - Bowens, Elinchrom, Lencarta - will be fine because they can all be relied upon to perform consistently for a long time and they all have the modifiers and light shapers that you're going to need.
It then comes down to personal choice and the cost of light shapers/modifiers. I'm probably biased because I'm involved with Lencarta, but I find my Lencarta equipment ideal for everything that I do. Having said that, a few years ago I spent heavily on Elinchrom (the pro mains powered generator units) and will happily recommend them for anyone who has a real need for very high power flash systems, for example photographing large interiors, or shooting products on 5" x 4" film - it's all horses for courses.
