How do you consider it moving up when going from separates to an integrated amp that has less output power as well as less amperes? Although going from 400wpc to 175wpc is only about a 3.5 db decrease in power, the mono amps put out 56 amperes as opposed to 42 amperes on the integrated which means it may not have the current to drive speakers with difficult loads. I know the Focals are easy to drive, but if you ever got the itch to upgrade the speakers, you may be wishing for more current.
It would make better sense to upgrade the separates instead. Going with the integrated, I would call it maybe a lateral move at best.