Thank you and appreciate for all the advices. Just to update my finding and I had success migrate the box. Both method works, I use the direct method of course.
Direct 1100 -> 1550
Upgrade1100 to R77.20.80
Upgrade 1550 to R80.20.40
Backup 1100 configuration and restore to 1550.
All configuration are restored (I have a little issue only the DHCP Setting - DNS Server is wrong).
SIC connection to Management Server will remain.
Push Policy from Management Server
2 Steps 1100 -> 1490 -> 1550
Upgrade1100 to R77.20.80
Upgrade 1490 to R77.20.87
Backup 1100 configuration and restore to 1490.
Backup 1490 configuration and restore to 1550.
1550 can be in factory firmware R80.20.15 or upgraded R80.20.40
All configuration are restored