TheSimeon, read my reply to cleochiro that I wrote today as this should answer some of your questions.
Your old MacGregor blades do not have any bounce whatsoever and they also have flat soles from front to back. Also, the center of gravity is way to high for obtaining really good consistency of hit. While a properly designed wider sole will help with your fat shots, you may have a swing plane problem meaning you are coming into the ball too steeply, which can be casued by a number of things. Being a new golfer I would recommend seeing a PGA professional and taking a half hour lesson.
I feel either the KE4 or the Glider “T” will help you. I would recommend that you get a #6 iron head only of each assembled with the same shaft such as the FST Pro 115 in an “R” flex. This shaft has a very soft tip. You can then compare them to your MacGregor’s as a very good starting point in the fitting process.