Get the TB adapter from ZZperformance, and the Series III aluminum upper intake manifold from www.gmpartsdirect.com
-you'll have to get the part # from the dealer (most likely he won't give it to you), or just ask over at www.clubgp.com
Series III UIM to my door will only be $106 -not bad, and it will probably be within $2-3 of that for your brother.
And yes, $1000 is off the scale -it should only take them 1.5-3 hrs of labor to replace it.
So let'* see:
3hrs shop labor: $195 ($65/hr)
Series III upper Intake Mani $110
Series II TB -Series III adapter: $75-90
Gaskets: $30 (max)
Coolant: $25 (max)
Oil/filter/Lube: $30 (max)
Injector O-rings $3-5
Misc fee'*: $50-75
Grand Total: .....Um -should be under $575 -at $1000 someone is getting themselves a $400+ tip.
Good luck, any good general repair shop around town should be willing to do it for under $300 as long as you supply the parts.
And if you (or your brother) are somewhat mechanically inclined you should be able to have it done for under $300-350.