Hm you know you have a great passion for sigs and because I'm an awsome person (*drools*) I'll give you a tipo if you don't want to be bothered with those texts with shadows and glowings!
In dafont.com you can go here Fancy > Distorted fonts | dafont.com and the types of fonts are already kind of worked and stylish so all you have to do is insert the text with a colour that matches the sig! ^^

For brushes I'd advice you to use heavy set of brushes! Of course some might think of traffic in downloads and things like that but if you download these brushes

Abstract pack 2 by ~Mavido on deviantART
VECTOR-LINEDOTS - HQ by *IHEA on deviantART
Pack 1: Assorted Brushes by ~xyunaxfantasiesx on deviantART

And also I don't know if Photoshop have it but I'm pretty sure it does, try to use SoftLight and Screen on the Layer options like the opacity. If you mix the gradient colours and then change the opacity and repeat that in different layers, your sig will come out awsome!

Btw does PS has these names?:
- Sample Colorize
- Gradient Map