Engine rebuild

[Fraidy]

'90 Corolla LE 5spd w/4A-FE, 205k miles. I had some kind of a knocking sound coming from the rear of the engine at low idle (600-800 rpm), but would go away above 800 rpm. It sounded like a rod knock. I was under the impression that a rod knock would be present throughout the rpm range. I have since pulled the engine out and am going to go through it. What are the common trouble areas for these engines? My plan is to make this thing bullet-proof and then install it in a southern/western rust-free body so I can get another 300-400k miles out of it with none other than routine maintenance. So far I have removed the head and taken out the camshafts. The bearings and journals look like they're almost new. There is an ever so slight ridge at the top of the stroke and you can still see the cross hatch marks from the factory honing of the cylinder walls. Someone suggested that I replace the connecting rods with lightweight forged rods to reduce the inertia and therefore reduce the wear on the connecting rod bearings. Any idea where I might find some and what brand I should be looking for. I plan on having the crank checked out meticulously for any signs of wear or out of balance condition. What else should I be looking for?

Any/all advice/suggestions will be greatly appreciated. Thanks for your time and consideration.