Would the straw be just for bedding? I think most people just use extra timothy hay so they have food as well. Either way, I would look for a local feed shop where you could buy a bale.
As for bonding, there’s some great info to get you started here: https://binkybunny.com/infocategory/bonding/
Usually it’s good to wait 3-4 weeks after neutering to start the actual dates to allow their hormones to drain from their system. The key things you’ll need are a “neutral territory” (an area where neither bunny has been) and lots of patience. 🙂 Once their hormones are settled you will do supervised “dates” in the neutral territory and prevent fighting (super important to prevent as much as possible). I like to start with some short sessions to get a sense of how they are together, then you can start increasing the length of sessions. There are lots of tips and tricks but sometimes it makes sense to just see how they do at first and go from there. 🙂
Ultimately the goal is to have them spend at least 48 hrs together (supervised) with no fighting or aggression, and lots of positive behaviors (grooming, cuddling, sharing litter box, etc).
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The answers provided in this discussion are for general guideline purposes only. The information is not intended to diagnose or treat your pet. Seek the advice of your veterinarian or a qualified behaviorist.