Advice on cleaning up this short block
 

I have an 04' LM7. I tore it down to see what the condition it's in and it look like it's still good. It's been on my stand a few days now with no heads and no oil pan.
Cheap route: If I decide to button it back up, how should I clean it up so that I know the water passages are clean, no debri in the cylinders or rotating assembly. Basicly clean it up to paint the block and put it back together.

I could clean it with simple green and brushes/scotch pads and hose it out. Then blow it off/out and wipe the insides down with fresh motor oil to coat everything before putting it back together.
Good or bad idea???

Expensive route: I also have the ability to score a set of 4.8L pistons for cheap, maybe free. If I go ahead and run these then I'm looking at the shop cleaning up the block, hone job, and putting back together with new rings, seals, and bearings.

Either option will be getting a new oil pump, LS2 timing chain, and a new cam.
Are the 4.8 pistons worth spending all the extra $$$. And yes I know i will also have piece of mind knowing it's all fresh.
But I can easily score another 5.3L to have on the stand as a backup for down the road.
If you were to go the cheap route, how would you clean up the short block?

http://i7.photobucket.com/albums/y27...8.jpg~original

http://i7.photobucket.com/albums/y27...1.jpg~original

http://i7.photobucket.com/albums/y27...b.jpg~original

http://i7.photobucket.com/albums/y27...3.jpg~original

No opinions on this?

I'm interested to know what advice you receive. good luck.