Question
how to best support them once they get to tall?

Answer
Good morning, Kenny!

The best staking materials are often those that are the least obtrusive.  I personally like bamboo stakes, but another alternative is twiggy branches from your own yard.

Try putting bamboo poles around the perimeter of the clump and close to the stems ?don抰 stick them into the roots! Then take some twine and loop around the stakes. This should help to support the entire clump. The bigger the clump, the bigger the stakes.

Or, if you have twiggy material from your own yard, from pruning, it can also be used if it is substantial enough.

Another thought is that if they are cut and come again flowers.  If you cut them lower they will come back busier and need less support.

And you might divide them next year, which will also contain their rambunctiousness a bit.
Does this help? Please feel free to write again.

Donna