Beginner Golfer - Old Ping ISI K Irons or Cheap Forgiving Box Set?

[SweetPotatoIQ]

Quick background.  Beginner skill level golfer here.  I've played on and off for the past decade, but never more than a few rounds per season.  Never shot under 100, or really even close.

I've always been above average fitness/athleticism/coordination, but unlike other activities that I've been able to get by with those attributes, golf has eluded me.

I have finally decided to take the game a bit more seriously after my most recent disastrous outing  It was one of the only times I can remember wanting off the course because it was more frustrating than fun.  Even in the midst of a bad round, I can usually put things in perspective and simply enjoy the ambiance of the golf course. Not this last time.  I was swinging too hard, flailing the arms like a mad man, no rhythm, etc.  I picked up the ball on over half the holes.  It was a nightmare.

I hit the web in search of the most basic fundamental golf swing concepts.  I'm not looking to hit my driver.  I'm not looking to hit 200+ yd iron shots.  I just want the ball to stay in the field of play and advance towards the hole so I have a shot at under 100.  I found a few key things about what the swing plane should look like, and a few checkpoints throughout the swing.  I'm now swinging at maybe 2/3rds the power from before, but making much more consistent contact.  Even my bad shots wouldn't be hole killers.  I haven't taken this to the course yet.  Only my backyard and a driving range.  But I'm confident it will be an improvement from last time.

With background to the side, I'm wondering if I should spend a couple hundred bucks on a cheap $200-$300 beginner box set of clubs like Callaway Strata or Wilson Profile XD.  I'm currently using some older 90's clubs from my wife's late grandfather, Ping ISI K clubs.  With the goal of hitting nothing more then a soft/straight shot, would it behoove me to find a set of cheap beginner clubs where the primary focus is to be forgiving for a beginner like myself?  Has technology changed enough in the last 20 years that a beginning like myself who isn't looking to shape a shot, but just make solid contact with the ball notice?

Thanks for any input.