i have 2 years flying experience and have mastered my pt 40 trainer.
i also fly a altech tamecat quite frequently
i was wondering about a global pt 19 as my 1st low wing taildragger
any thoughts

Let's assume that you can fly the trainer properly, meaning you tell the plane where to go and it will ... the following planes are great low wing planes:

Phoenix Scanner - easy to built and will fly nice. Its cheap and will not stall easily
WM T34 Mentor - relatively cheap and it super nice to fly ... smooth as silk ... easy to fly and landings are a breeze
WM Super Sport - very agile for a low wing sport plane (mine will KE across the field without mixing), will come in for landing slightly hot unless you flare her, hence if you are really good on your trainer you can handle this one
Seagull Tucano - its nice and the new batch are very well made for its price, handles easy but not as easy as the T34 Mentor

Everyone else will recomment the 4* and Tiger II, I never had them but I guess they must be good stuff.

I dont know anything about the PT19, but I can definitely recommend the Four Star 60 or the Tiger II, if you are wanting a taildragger. Neither the Tucano or the T34 listed in the above post are taildraggers, so that leaves them out. Both the Four Star and the Tiger II are responsive enough to continue building your skills and do good aerobatics, and still be easy to land.

While I am not familliar with the Global PT-19, a PT-19 in general is a fairly docile low-wing plane, so if you have your heart set on one, you probably handle it. Of course, it would be a good idea to have a more experienced flier maiden it for you.

Ditto

SIG Fourstar 40,60.