Best hair products to make your hair hard and wavy for straight hair?

My natural hair is kinky/wavy so I usually put a relaxer in it for two-five minutes and once it's out, my hair is completely straight. So, I usually put gel in my hair so that it has a slight wave to it. I usually use infusium 23 and tresemme, but I think that my hair has gotten used to it because my hair is no longer hard-ish. What else should I use? If I don't put anything in it, it's straight with a bit waves.

This is what my hair looks like without products (besides it's thicker and slightly poofy)

http://www.focusonstyle.com/frontrow/ima...

This is what it looks like with gel, etc.

http://www.teen-prom-dresses.com/images/...

Best hair products to make your hair hard and wavy for straight hair?

TIGI Catwalk CURLS ROCK Curl AMPLIFIER

I use it and love it!