need ideas or opinions on this.

[MSL]

Well now that i got my fuel pump done i need to do my harmonic balancer. i took my truck to a few shops to ask about it wobbling they say it is worn out or someone beat it on so know im out to change it. what i need to know is when i pull it off what do i need to look for to get a balancer to match close to it. also should i buy a new one or go to the wrecking yard and pick one up. also i have to change the pullys the lower and upper one have a extra slot for a/c wich i dont have so i need any ideas on wich ones to get. thanks