Is there a performance parts shop or local track in your area?
Someone there should be able to direct you to someone who knows a good shop to use.
My 4x4 was done at a quality shop that knew as soon as I asked for a Y-pipe install,
that I would also want mandrel bent stainless steel pipe sections to replace the squash bent sections they remove for a smoother flow.
Stock crush bent y-pipe:
New Magnaflow Y $27
The cheap crushed bent aluminum bargain exhaust shop crap would defeat the purpose of doing a performance Y install (IMHO).
Why? because a single crushed 90º bend can decrease flow by almost 20% , add up a number of bends and you just wasted your money.
Here's mine installed with 2 large smooth transition Mandrel Bent Stainless Steel sections (only $15 ea)
So about $60 in parts, and no more than $90 in labor to get it done right.