I can't see any reason why those style lights wouldn't work for your situation, as long as they come with an electrical box to safely make the wire connections, which the ones I've used in the past did.

As far as lighting layout I like to put plenty. Staying about a foot away from cabinets, one every 4 or 5 feet on a grid, maybe lining up with the centerline of your upper cabinets or other features you have going on. Throw some pieces of blue tape on the ceiling where you think you'd like them and try to imagine how much light they'll give.

As far as brand, choose whatever has the most pleasing aesthetic to you, and comes in a color temperature you enjoy, some even have the option to change the temperature. Otherwise any reputable brands LEDs should last for years to come.

On a side note about keeping the drop ceiling vs drywall, I find it hard to imagine why you couldn't frame in the electrical and plumbing and have drywall instead of ceiling tile, albeit at the same height, if you wished.

WD Cruise's information is incorrect. He is basing his reply on the old fashioned 'Can' style recessed lights. You clearly stated 'wafer' style LED's. I want to do the same job and I'm debating to use a backing plate on the top side of the tile. The other consideration is using a more robust tile instead of the fibreglass wafer ones.

@montmurf correct, I meant the very thin wafer type with remote junction box, no real can whatsoever. I checked with a local licensed electrician and he said it was totally fine even without the mounting plate, and we asked him to help us do the rewiring. He did a great job! I simply cut holes in the new drop ceiling tile with an adjustable hole saw and popped in the lights connecting them to the junction box (simple screw on connection). Our local electrical code does not require the remote j-boxes to be mounted but some do, so make sure you check yours out before proceeding. Lithonia lighting told me the mounting plates are there to just provide extra support if the tiles you have aren't especially strong and also to provide a place to mount the remote j-box; they are not required in all applications, depending on the local electrical code. I don't think it hurts to do it either way. Using the mounting plates would give you extra peace of mind though, especially if your tiles are flimsy. I used Lumawash tiles from Armstrong and they have been great. Been running the wafer lights for about 2 months now, no issues thus far, but I'll pop back in with a summer update too.

@Jordan Swogger - Looking to do the exact same thing. Have existing can lights in an exposed basement ceiling. I want to put in drop ceiling 3-4 inches below it to conceal the plumbing/ductwork, but really don't want to swap the can lights. I've already swapped the lights with the retrofit LEDs which nicely screw into the old can light fixture. It all seems pretty simple, and assuming there is no safety/fire risks with plugging the LED retrofit directly into the ceiling tile, should work fine. Just checked and there is even plenty of slack in the existing connection wiring.

One question - how did you keep the retrofit LED lights mounted tightly to the ceiling? How do you keep tension on the backside so that the light does not fall through? Also, no concern or risk of heat from LED directly onto ceiling tile?

Any help greatly appreciated!

The flat LED retrofit lights weigh very little even with the j box the spring mouse trap clamps hold the lights up just fine