For the OP;
The engine oiling system has nothing to do with exhaust note. Side oiler, top oiler, no oiler — no difference in exhaust note.
Your engine sound wil be primarily affected by your compression ratio, camshaft lobe separation angle (LSA) and your cam phasing. There are excellent sounding big blocks, small blocks and even transplants like certain GM engines.
Any of the modern 4V EFI equipped engines will disappoint you with respect to the exhaust note. They tend to be sewing machine like in their idle note consistency — no audible change in note. They are reliable, start in any weather, don't leak
oil and some make monstrous power.
In the end this
Advanced Engine Decision Tree Logic Chart will probably be the most helpful for you;
p.s. Your first consideration should be getting it through Australian certification. Once you have done that you can always put the camshaft in that produces the exhaust note you want.