Which spreader to get? Well, that depends on what brand of fert your going to settle on for your applications.
If you were to look at the backside of the Fert bags, you will see recommended settings for given brands of spreaders. There is no industry standard on output/rate or area of spread among manufacturers.
How in the world otherwise would you know how much coverage or rate you're applying? Even if you were to match up the fert with the spreader, it's still recommended you calibrate your application rate which can vary by applicator walking speed etc.
So if you decide on Lesco, go with a Lesco spreader etc. Even if you don't actually calibrate it for yourself (with the use of trays) it's assumed your likely to be close. I suggest you do some study and get some formal training on this before you do a bad application and possibly be sued and/or fined for damages etc. FYI: In my area, you cannot apply insecticides or herbicides to any open lawn areas without full applicators license > >> "Read" weed and feeds...... Yes, Homeowners can BUT you may NOT to a homeowner's or any property- even without pay.