A family member of mine recently started her own business 'Beautiful Bespoke Balloons', if you're looking for personalised/custom balloons for an event then please consider supporting her! ^^
https://www.instagram.com/bespokeeballoonsss/

I do not know the details of how the balloons are transported or how personalised they can be, I believe you must be in the area to order (this business is based in England, more specific details are in the Instagram bio), please contact the owner and not me for more details. If you do not live in the same area then please consider supporting her small business by advertising to more people.