Infopath is still supported by Microsoft but not being updated and wont have another version. Microsoft has promised us there will be an upgrade path to whatever is next. However - it's been a year since that announcement but we have not seen anything come out of Redmond. My advice is stay away from InfoPath path.
You didn't indicate your platform - but MS is pushing more towards using Access Apps for custom forms in O365. You can do this on premise too if it's configured.
Another option only available in O365 is using Excel Forms. This has not yet made it's way to on-premise office web apps servers. I'm light on these so not sure if they can handle your conditional logic, it's something you would need to explore.