More than one way to skin a cat for sure.
i think my main reason for the flat tappet cam preference is the low cost and wider selection.

That Summit cam kit is probably under $110.

I'm pretty sure the factory 318 flat tappet cam is a 110lsa.

In 1990-ish I built a low buck 318.
Rebuilder cast pistons, mild port work on some open chamber 318 heads(flowed around 180), std performer intake, 600vs Holley, 1-5/8" headers, 340 cam and springs.
I don't remember the tq but it was about 275hp on the dyno..... And I seem to recall it peaked solidly over 5000rpm(like 5500-5700).

I'll have to see if I still have the dyno sheets.