J-30 member just acquired a '99 Q45T...

[truckmen]

Hello all,

I've just acquired a non-running '99 Q45T in white pearl. Thought I'd drop a line to say hello.
If I am not mistaken, the '99 is considered the 2nd generation model of this line?

We don't know what's wrong with the car at this time but will be looking at it late today after we return with a new battery.
By the way, anyone know of some good sources for parts for the '99 Q45T?

I am beginning my search with a the plastic battery tray. There are some numbers on this one:
Nissan Part Number P550-5710-100

[truckmen]

UPDATE:
It starts, with difficulty! But, I believe I may not need a starter.
But also found out that the catalytic converters were cut off (probably stolen) and I need to buy a pair of them.

Any ideas on reasonably-priced correct fits?

UPDATE (part 2),
The engine started and after throwing some fresh gas, got it to run steady. I discovered that this engine has a very loud "rod knock" sound. However, no "engine check light" comes on nor does the engine run all that rough.
I revved up the motor in park to ~2000 RPM and the "knock" speeds up in sync. As the engine drops back down to idle, the knock gets very loud during part of the idle-down. My spotty experience tells me that this is a rod knock. Could anyone concur? I know that oil pumps can also make a similar sound when they "go out".
Now, what I need to do is to find a way to determine for sure that it is a rod. If so, the question then presents itself:

Would you find a replacement motor or fix the current one?