Yes it is possible. Western Union accepts online transactions on some countries just follow the guide on www.donation.myroserver.com
then Western Union link.
If doing an online transaction just printscreen the payment page that indicates the MTCN number.
Yes it is possible to choose on the freebie wanted. You may choose from promo 45P + 2 AES or the 1 Free Item of Choice (gpipe, pdag, emg, gmg) + 2 AES.
Thank you for your interest in donating.