DIY Aquarium Plants?

I love Vallis in the aquarium, because you can make some really nice flowing plant scenes and they move really nicely in the water. The problem is I can't get the vallis I have in my aquarium to stay alive particularly long, mainly because of the poor design of my tank (the filter and light are in the hood, and they are so close together that the back half of the tank can't be reached by much light). This means that the strongest light is at the front of the tank and an aquarium IMO is always better with the plants not right up at the glass so you can see the fish in the setting.

The synthetic vallis looking plants I have stay rigid in the tank, all of them silk ones. Would it be possible to make my own vallis-type synthetic plant you think? Out of more flowing fabrics? How would I go about having the right colour without using dyes which would be harmful to fish?

Is it possible at all? Thanks.

...You know, this is a good excuse to go out and buy another tank...