Lighting: Take a 300px soft brush and select the color White. Click just below on above the Render/Focal that you have. Then lower the opacity just a tiny bit. Theres a good light source.
Text Blending: If you know how to make a clipping mask, make a new layer, go to Image > Apply Image then click ok. Then click the Eye beside that layer. Then select the text tool and click on the layer below the hidden applied image you just made. ( This will cause the text to appear below the applied image.) Then type your text. Then click the eye on the Applied Image layer again. Then right click it, Select Mask Clipping or whatever. Then move that layer around till you like it.
If you dont like that effect then just select your text tool, and change the color of the text to the dominant color of the Signature.