For Fightcade all you gotta do is
-make an account
-download the client
-download some roms https://mega.nz/#F!EoJjwSLB!Tukuk9bZAa7YXXxKNVHorw
(may as well grab all of them since sometimes it can be hard to tell right away which a game needs since some roms depend on other roms)
-put the roms in the rom folder
-start client, log in
-click a game's lobby on the left
-click the icon to the left of your name in the room to launch the game
-in the window that opens, in the upper left click Game -> Map game inputs and set your controls
-return back to lobby
-click the icon next to the name of whoever you want to challenge, if they accept, the game window will open and you'll be playing together! If you lose, press whatever you bound Start to to get back to the character select screen and fight again. If you've been winning and want to change characters, or need to reset the game for some other reason, press F3
Sounds like a bit of work but it's very straightforward once you get it set up. You can also change the amount of input delay in the fightcade window's Settings -> Smoothing/input lag. 1-3 seems like a safe bet for most, but if you're seeing teleporting or things acting strangely you might want to turn it up a few frames. Note that I'm in New Zealand and can play with my American friend at 1f delay with only the only bit of rollback. I could probably play on 2 without any rollback, but ehhhhhh…
Arcade sticks are great, but a gamepad is perfectly fine as well. Some people seem to have trouble using keyboard for fightcade games since they tend to not have the input auto-corrects/shortcuts that more modern PC/console fighting games have, but you could probably get used to it.
If there's enough interest we can start a discord or steam group or something, since FC I don't think has a friends list function.