That tonestyler isn't cheap, but man, it's awesome. I've got one in my #1 and I find it incredibly useful.
I did to and I was amazed for how I can passively shape my tone . Now I have other option switable for you :
1)build and home made tone styler (I did and I can design a wiring for it so simple and funny project) ,
2) use push pull pots for adding and removing treble bleed(on the volume pot) and 2 caps switch on the tone pot ,
3)simple homemade 2 band passive eq(two stacked tone pots , 2 resistor and 1 cap) .
All these are good because you don't need battery and wood work .