First, he is absolutely gorgeous so I understand why you are in love with him. He will be getting a loving home, so it’s a nice move for him.
Regarding the exposure to, and reoccurance of, the e. cunniculi in Hodari, I would ask for a meeting with my vet to discuss it in detail. Your vet is the one most familiar with Hodari’s situation and risks, and if there is either preventative care for the new guy, or stress reducing measures for Hodari, your vet is the one to give you that hands on help. I just think that medical expertise with knowledge of your specific needs is your best bet for advice.
I wouldn’t worry about Hodari being left with a sitter. Staying in familiar home, and having the same basic routine, is the least stressful. Write up detailed instructions of what you regularly do for food, and at what times of the day and night so that will be easily repeated. Limited out time is fine. Even confining Hodari to the habitat for 2 days won’t hurt at all, if you are worried that the sitter can’t handle play time. Just have an emergency contact list of vet and friends or family that can help prepared, and be available yourself by phone. That’s just in case, though. I doubt you’ll have a problem on Hodari’s end.
But H. will definitely smell Rubani on you and in the house. Is there any chance of taking Rubani directly to a vet for a neuter before you take him home? My thinking is that he can have the procedure done, go home with you and recover quietly in a new habitat in your house. His hormones won’t settle down for a month, but the whole stress of travel, change and neuter will get overwith and be behind him once he’s in his new home. You will be safe to begin bonding them in 4 weeks. He’ll be much easier to handle then.
He will need to adjust to you and your home first, with just an initial awareness of Hodari. I think you should give H. a surrogate bunny to snuggle for the next few weeks, so H’s scent gets on it. You can ask the breeder to give R. a surrogate stuffy animal as well. You can then exchange them once he’s in your house so each of them can smell the other on the stuffed toy. It will make the smell gradually familiar and assist the bonding process. (And take on any hostilities from either, instead of the real thing.)
Travel – a travel carrier is OK. A small starter cage can fit on a back seat pretty well and a litter pan can be inside it, with hay to munch. Keep bottled water handy and provide a drink in a small cup during breaks. A water bottle could be hung, but often drips in a car ride, so if you use it, hang it over the litter pan. No bedding, but a blankie (or the stuffed toy) to snuggle can provide comfort and traction in a moving vehicle. Wet greens to eat can provide the water if it’s too sloshy to have straight water on the move. I drove with my bunny for 3 days from MA to FL and he was fine in a small cage. Have a towel handy in case his feet get wet, or he’ll get sore hocks.
I think you have a lot to look forward to. Good luck!