@BenjaIRL
Wait! You are making a very big mistake,
"Tokyo Monorail" is NOT "JR-EAST", different rail company.
So you can not buy Monorail Suica at "JR EAST Travel Service Center" in HND.
It means Tokyo Monorail IC card "Monorail Suica" can not be returned to JR-EAST.
Also JR-EAST IC card "Suica" can not be returned to Tokyo Monorail.
Just there is no big difference between the basic functions of both cards.
In the case of the metropolitan(Tokyo and around wide) area,
you can use either in JR-EAST, Tokyo Monorail, or even in "Rinkai Suica" and "PASMO" card area's
most trains and buses, you should read below their official web's guide and FAQ.
In HND(Int'l terminal) IC card salers and you can buy it is,
Suica : by JR-EAST, at JR EAST Travel Service Center (counter, No vending machine of Suica)
https://www.jreast.co.jp/e/pass/suica.htmlMonorail Suica : by Tokyo Monorail, regular ticket vending machine.
http://www.tokyo-monorail.co.jp/english/tickets/suica/Rinkai Suica : by TWR(Rinkai Line is official nick), No sales in HND.
https://www.twr.co.jp/en/tabid/234/Default.aspx#ticket05PASMO : by Non-JR rail and bus companies group except above two different Suica using companies,
at KEIKYU regular ticket vending machine.
https://www.pasmo.co.jp/en/https://www.haneda-tokyo-access.com/en/https://www.haneda-tokyo-access.com/en/ticket/pasmo.html