You can't go wrong with the Babylock. I have several of their sergers. Love them all.
BTW morethanvacsew.com has the vibrant for 349.00. If you call kenssewingcenter.com ask for Kevin, see if he will match the price. I HAVE PURCHASED MANY MACHINES FROM THEM DURING THE LAST TEN YEARS. I DONT KNOW THE FOLKS AT MORETHANVACSEW...sorry for the caps, my tablet has a mind of its own.
I am not affiliated with either one. But I do know that kenssewing.com has excellent service and help if you need it. They also have a bonus of two months of the BABYLOCK ideas videos and other perks as a bonus.