Upgrade ISR4321

[bilal-elkadi89]

Hello everyone

I have a Cisco ISR4321

I want to do an upgrade, please find details and share with me your thoughts :

Current ROMMON : 16.12(2r) ( no newer version that this, if im not mistaken )
Current IOS XE Firmware : 17.03.05

From the Software Download : https://software.cisco.com/download/home/286006221/type/282046477/release/Amsterdam-17.3.5

The recommended Firmware is : 
Release Dublin-17.12.5a MD
Release Cupertino-17.9.7a MD

My questions is : 
Since the ROMMON version is up to date, Is it possible to Upgrade only the IOS-XE Firmware ?
Suppose I can upgrade to IOS-XE Firmware, what is the upgrade path to one of those Firmware : 
Release Dublin-17.12.5a MD
Release Cupertino-17.9.7a MD

Could you please help me