Bish - I'll field your question if i may...
In a pinch, you might get away with painting the regular field grey tunic to make it look tropical. Though there are some subtle differences, the biggest problem would be the footwear - these were the canvas type, laced up front for both ankle, and the less popular full length boot.
Anyhow, back to the tunic, the major differences:
-DAK tunics were made to be worn open collared and had fashioned lapels, unlike the regular field grey tunic which could be buttoned all the way up. So that would mean one less button up front.
-the material was lighter, durable cotton material to be more precise.
-the tunic went through three design changes with regards to the pockets: initially the four pockets had pleats and scalloped flaps. A second pattern arrived in late '42 with no pleats. In early 1943, the third pattern had straight flaps on the pockets.
I'll post another response for some figure suggestions...
hth
... and btw, nice work on your Pz III thus far.
regards,
Jack