Urgent help with tiles!!!

I'm Brazilian and I'm using google translator, sorry if the translation is not 100% accurate, but let's go...
I'm trying to create a pok?mon fan game with RPG Maker XP, I already created the history and the maps in my head, but I want it to be in pokemon soul silver and heart gold tilesets...
Here comes the problem ... I never find tiles that I enjoy and when I encounter they are always parts in different tiles, then I use a photoshop to unite them, always in 32x32 format to work in the rpg maker, but always ends up smearing the edges of some tiles, or at the time of leaving them transparent some white tiles are transparent also ...

Is there any way or any trick for me to get the tilesets right?
Besides the big problem I will leave some questions too, thank you if anyone can answer me ...
32x32 is correct?
The most difficult to find are tiles of lakes / sea / waterfall, and when I think ... how do I create autotiiles to make the water lively?

it's hard to find tileets that match ...
Thank you to anyone who can help me.

Could you show me an example for the actual images you're using and then after you've edited so I could get a better of idea of what's happening?

Nina said:

Could you show me an example for the actual images you're using and then after you've edited so I could get a better of idea of what's happening?

Click to expand...

Thanks Nina,follows some photos...

I made 32x32 squares in pink and blue to align the tiles right in rpgmaker xp, and for the time to leave transparent the white tiles do not become transparent also if the background is white.
I found some tiles out there and I was putting parts of them together, but the edges of the tiles (rivers and elevations for example) always end up stained and in the game some tilesets are not correctly aligned with one another.
I want to make the game on the graphic of soul silver.


some examples...
in pink and blue, at the time of leaving transparent always the edges stain, and the shadows of trees and stones absorb the color.
If I leave the white background to improve the image, the ice tiles, when it comes to leaving the image transparent, the ice white also turns off.
And in the pokemon center, I can not adjust tiles to be proportional (at the nurse's desk, along with the machine where pokeballs blink when they are being cured for example).
I want help with the right sizes and ways to make the tiles look right in shading and proportion.