Do I need to replace timing belt if replacing water pump?
any tips or advice on changing water pump appreciated even recommending which water pump to buy.

 

Is it a 3.3 or a 3.5 ?
3.3 is an external pump with a chain driven cam.
3.5 uses a Timing Belt to drive the cams and water pump and a new belt is a maintenance item so yes change it.
Although it is a non interference design it is recommended to change it. Later design 3.5's are interference engines and the belt MUST be replaced.

 

3.5 227620 miles

 

That belt owes you nothing, should have been replaced at least twice already.
Defiantly Replace it

 

I might not have to replace water pump. I’m trying to solve why car is overheating. I added coolant, but I think it got air bubbles. I left radiator cap off, added coolant, and revved car. Coolant bubbled out of overflow. Loosened bleeder. Coolant went into system. Kept doing that over and over, but now it is overheating.

 

Head Gasket damaged