Hello JamJar
You could look also at Bansuri flutes. They are transverse flute used for Indian music. They are very simple in design. They are not chromatic but they usualy are not expensive so you can buy several that are in different keys.
Irish flute are not chromatic neither and are generaly in the key of D. They can be chromatic by the addition of keys. 4 is the minimum to make the flute fully chromatic and 6 is kind of the standard. Good irish flutes tend to be more expensive that good Bansuri flutes.
I think that you might be disappointed by a baroque traverso if you are going to play rock music. Traverso are very flexible instruments that need an excelent hear to be played chromaticaly. You will find it difficult to play in tune with the other instruments in your band. I really think that a Boehm flute, even if it looks more complicated, is really a better instrument for you purpose. Just my 2 cents...
Patrick