It’s got ‘other amount’ and Paypal, can’t make it more convenient and safe for worldwide donations really.
Wikipedia does it the same way for years now.
You just need to make sure that the email address you use is the one that you’re registered at with Paypal, otherwise Paypal might not do the transaction.
IMHO, if you do the transaction via Paypal, your own bank will only see a transaction to Paypal (I think the note field will have some clue though for yourself), but shouldn’t have info about where it actually went (re your fear of being associated with money laundering or tax evasion 
), that’s on Paypals turf. I naturally have no idea what you intend to donate, and at which level financial authorities are being triggered, but you mentioning ~120USD being a lot for you I’d say you’re really really safe from that happening. 
PS: I’ve been using Paypal for over 10 years now (usually ebay, but also couple of times outside of ebay) - never had a problem. Any other payment I do internationally involves credit cards - due to the more favorable Forex rates I get at GEmoney and/or Citibank, if amounts go over like a 100 bucks or so.