I've found the locations for Body Armor that are closest to the houses of Michael, Trevor, and Franklin. However, these are all look like Super Light Armor when you are picking them up. That is the worst of the body armors and costs $400 at Ammu*nation. However, if you pick up the armor and then go into an Ammu*nation, it will show you that you are wearing Super Heavy Armor, which normally costs $2000.
So, is the body armor that you can find always Super Heavy Armor and just has the wrong graphic when you pick it up?
Locations: Franklin - none right next to his house that I've seen. There is one in the Sheriff's parking lot right behind where you do the towing mission, which is fairly close. Pull into the towing lot, then walk through the wire fence door and head to the toward the right by the building. Michael - go to the parking lot across from the Epilson building south of Michael's house and on the east side of the parking lot is the body armor Trevor - by the generator at the front of the Sandy Shores Medical Center just down the street from Trevor's house. This is the easiest to grab and given the types of missions Trevor does, you'll want it ;-)
Okay, courtesy of Lockeadon in another thread there is a very good one for Franklin, simply because it is relatively close and comes with a whole bunch of other benefits in the form of a health pack and $7500 briefcase. However, if you don't want early free money, then don't use this one, I'll put a spoilers space so you can skip the rest of the post...
Lockeadon says... "every hidden package respawns just like other power-ups and one in particular (which has 7500$ every time you collect it) is close enough to the surface that its obtainable without training lung capacity. its located in the canal with two bridges over it, one a trainbridge and one a real one, southeast of franklins safehouse and those bridges cross over to the industrial area down there. the package is on the top deck of the underwater barge with a few weapons scattered around down there (pistol, crowbar, armor, health pickups that i found). so what you can do is use that one till your lung capacity improves then switch to the more lucrative hidden package locations as you become able to reach them"
The location is just a bit east and of the train bridge underwater, just south of the nearest land and further east is the bridge for the cars leading into the industrial area. Once you find the spot, just make note of it and then wait until you unlock Michael. Now, take one or the other to the spot, swim down, grab the money, vest, etc. then switch to the other character and then immediately switch back and collect more money. Repeat until you have enough for playing in the stock market or just wait until you unlock Trevor and get to the point where you can purchase real estate. By then you'll have done a heist and money shouldn't be an issue for the rest of the game.
Note that if you die because you didn't get to the surface or switch to the other character and back properly you'll probably be at a hospital east of Franklin's house and heading almost due south back to the water you can start the process over again.
Michael - go to the parking lot across from the Epilson building south of Michael's house and on the east side of the parking lot is the body armor
Could you please clarify what parking lot you are talking about? The only one nearby is a small elevated one to the south of the epsilon building but there's no armor anywhere around there.
Go to the episilon building and it is the one north of it. The armor is found on the east side next to a sign that says parking. You cannot enter the lot, but there is an entrance with the parking sign. The armor is in the corner. I had a hard time with this one too.