A medical bracelet would not be a bad idea at all.
Are you referring to the insulin pens that you can refill with cartridges? I'd go with four; two in use for both insulins and two spare? Spares of everything else you use and the right quantities to see you through the length of time you'll be away.
I don't know where you're going, but if it's around Europe then you should apply for one of these free insurance cards. It will help you avoid any hospital bills in the unfortunate event that you are hospitalised. Diabetes related or not:
https://www.gov.uk/european-health-insurance-card
Grant