I'm not sure that you are able to read in Thai or not. So, I will try my best to type in English.
PPV has a lots of good advantages, for example, durability, maintenance costs. On the other hand, the big disadvantages are hard suspension and the noise from outside.
MPV is a very good choice, If you want to drive on road. So the good choices are Wish and Space Wagon. Wish, in my opinion, it's too small and this generation has been released for long, so Space Wagon should be the best choice.
But the price of space wagon is a little bit higher than your budget so why don't you try Innova. If you want to save half of your budget, you just pick the lowest model. Its price is around 820,000 baht.