I think as long as it meets NMMA specs your good, Me I have a Suzuki also and use Suzuki oil because the guy at the parts desk gives me a good price on it.
I have a 140 Suzuki that I bought new in 2003. 2400 hrs and runs perfect! Used Suzuki oil for the first 5 yrs while it was still under warranty then got tired of paying 6.50 or more a quart. Been using the same 10-40 valvaline I run in my trucks with no problem whatsoever since then. 1 oil and filter change each spring, I do check the dipstick every month but never have to add any.
I pay $6 or $7 a quart for the Evinrude 4-stroke oil. But I suspect the $3 oil at Menards would work just fine. With an oil change only every 100 hours I figure why take a chance.