Privately select a few (10-15) RP corps small and down-about enough that they might actually NEED the isk. Ask them quietly what they do and how they operate. Those that (for all intents and purposes) work to boost their fellow members and what they do, say like building ships for members to use for free, missioning or mining of FW-plexing together or whatever in to get by. Essentially, those that aim to play the game and have fun together being active, not just enriching their personal wallets to do nothing in particular.
Then divide, say, 1-2 billion among their members so that each get's about 100-200 million, at most. You can use EVE-who to find the names of all their corp-members.
This way your money won't just be hoarded by some individual or greedy CEO somewhere and will go to several in numbers that are not overwhelming, but overall helpful. A corp of ten who all get 200 million is a corp that can lose A LOT of small ships in pursuit of their entertainment. Or a few bigger ones. Or help get all those high-end minerals they need to build even more ships.
Don't even have to be RP'ers only, really. Just whatever you do, don't dump it all on one lone guy somewhere, EVER. 20 billion in one guy' pocket is iing on the Ihavebillionsallready cake, or loads of money in some poor guy's pocket that will burn it's way out in the form of some idiotically pimped faction-something lost to a gank-party in low-sec or null, thus feeding someone other than what you intended.
Also; you bastard. If I were fortunate to hava 40 billion+ I'd use it myself, buy BPO's and a pos and mods and do research and acquire assets.
Hell I'd likely enact my long-standing pipe-dream of funding and founding my own corp somewhere. Here you are giving away half your money on a whim, you bastard.
Hah, I'm totally joking. Your awesome, I just hope your isk benefits more than one guy somewhere.