Jazz, how big and deep are your pots? How old are your roses? They are gorgeous BTW. What zone are you in?
Some varieties are just naturally "floppy" and some are more upright with stiffer canes. Some are floppy when they are babies and will "straighten up" more as the canes get older and bigger. The variety you have seems, from pictures I have seen to have more of a rounded bush type rather than "straight up" canes that grow tall.
I have grown roses in pots for years. I use several methods for my pots. First, I make sure that the roses have good root depth. I try to find pots at least 24 inches across and at least 20 inches in depth, if not more. I use a good houseplant potting soil in those pots so there is ample drainage, so my plants don't have "wet feet" which roses hate. I use screening on the bottom holes so the water can run straight through it and do not put gravel or pebbles on the bottom of the pot for drainage. I make sure they get ample sun (which for me may be a little less than you) depending on where you live. I also put the pots on a movable platform so I make sure they drain and the water coming through doesn't ruin the flooring below. I like these plastic ones from Australia as they can take the weight and can move and don't deteriorate like the wooden ones do.
I also use these metal rings to help keep my flowers upright. I have them all over my garden for plants in the ground and in my pots. The 18 x 24 size fits my 24 inch pots perfectly and the plant hides the ring from view. You don't have to use those particular ones but for me they are very sturdy and easy to "install" and "uninstall." This company has other plant supports that you can use as well. This company tends to be pricey as are the castors above, but they will last for years and years.
Charisma will grow (depending on your area) to be about 4--5 feet or so depending on where you live. You may need to put it in a large pot as it gets older.