Excellent read, with practical usable results. The Penrite 5W-60 looks good.
Don't go thinking that a thicker oil should be better. The engine manufacturer determines what oil viscosity suits the clearances in their engines, and too thick an oil will take longer to circulate on start up (increased wear), will run hotter and will make hydraulic tappets noisier (the thicker oil has trouble getting through to the tappets to act as an hydraulic oil).
Use the viscosity that the OEM recommends! They will include an ambient temperature vs oil viscosity chart in the owner's manual. DON'T just use a thicker oil because the viscosity numbers are higher. Thicker doesn't mean better.
Did you know what viscosity was most commonly used in New Zealand before the Morris Mini came onto the market with it's common engine and transmission lubrication and it's need for an SAE 20W-50 oil because of the lubrication requirements of the transmission gears? SAE10W-30. I know in the 90's in NZ, Mitsubishi had no end of problems with bore glazing because the owners and workshops were using an SAE 20W-50 engine oil on the assumption that a thicker oil was better and that left a thicker oil film on the cylinder walls which burnt, glazed and caused high oil consumption. This also had something to do with the Mitsubishi distributor owning an oil company which had an SAE20W-50 engine oil as it's main product. Mitsubishi cars using an SAE 15W-40 didn't experience this problem.