SC2Mapster

Ahh I see, sure.

So you want a Tank, a ranged attacker and a spell caster?

Well, there are many awesome models by sc2mapster author. As long as proper credits is given.

How about checking them out? Here are a few [in no particular order].

https://www.sc2mapster.com/projects/warcraft-1-structures/images

https://www.sc2mapster.com/projects/davespectres-assets/images

https://www.sc2mapster.com/projects/hammers-assets/images

https://www.sc2mapster.com/projects/dow-units/images

https://www.sc2mapster.com/projects/wingedarchon-assets/images

What abilities do you have in mind?

What heroes and what abilities do you have in mind?

If you have the time, try to check out the videos here down bellow. 

It might give you ideas of what heroes and what abilities are fairly possible to be implement for sc2.

It might give you ideas of what heroes and what abilities are fairly possible to be implement for sc2.