Need help with stereo switch box

[Simon Strauss]

I'm currently working on a switch box for the aux inputs on my stereo system and need some help figuring out what sort of resistance and other specs i am going to need in the switch. Its a 150 watt sharp system with only one aux input, and because splitting the input it is affecting my sound quality and volume, I'm planning on making an auxiliary input box with which i can switch between either four or five different inputs. The question i have is what sort of resistance am i going to need in the switch, I'm going to be running a turn table with a pre amp, my laptop, my bass guitar(i know I'm going to need to pre amp it first) and hopefully a TV when i go off to college through it and don't trust my local radio shack employees to answer this question for me.

Thanks for your help,
Simon