I honestly feel like reparations is not a bad idea, but anything that resetera would accept as being reparations will 100% be completely unrealistic.
On a moral level, sure. But it really should have happened at the end of the civil war, with the promised 40 acres and a mule.
Today?
It would have to work like a legal settlement; as in "Here's your money, in return you never get to complain about slavery or institutionalised racism ever again" because that money is supposed to address that and draw a line under it. Move on. People would be 'supposed' to use that money to do things like open businesses, create community banking schemes, community hospitals, community schools, community housing, political campaigning, and all the other things that would directly and meaningfully improve things. And if it isn't enough when combined as a community, bad luck, because thats all there is.
Just like any other lawsuit settlement. Its an apology you inherently accept by taking the payment.
In reality the people who use that money to benefit their communities are not going to be happy when in 10 years time the people who take that cash and piss it away on flatscreen TVs and sportscars are then giving
them shit about their 'privilege' and demanding more.
Other minorities (including black americans of voluntary immigrant descent) aren't going to be happy they didn't get shit, because they're not going to get reparations from the US if they weren't a victim of the US slave trade.
Anyone who's been screwed by 'the system' in general who don't happen to have slave ancestry are going to be equally as pissed for the same reasons.
It wouldn't solve any underlying tensions between the 'haves' and the 'have nots', it would just shuffle the pieces around a little.
Especially if the criteria for eligibility was based on being able to prove ancestry, or was based on some kind of existing 'citizenship' metric, such as the right to vote. Either way, a lot of people end up cut out of that.
The actual money raising isn't the tough part. You can print bonds, you can do a one off income percentile tax (on the assumption those doing best off now have benefitted the most from the system), or you can sell some assets, or take out some (more) loans. But you'd escalate resentment amongst the populace literally everywhere.
edit:
tl;dr - giving individuals a lump cash sum is about the worst possible way to try and fix anything.