Hello and Welcome!
If you want to see LOTS of habitat pics check out the habitat gallery:
https://binkybunny.com/BUNNYINFO/GreatHabitats/tabid/229/Default.aspx
I think most if not all the housing set ups there came from members here.
How old are your bunnies and are they spayed/neutered? Are they currently housed together? I’m asking because if they are opposite gender and not altered they will need to be housed separately until they are spayed/neutered and can be bonded. Even if they are same gender it’s usually a good idea to keep them separated until are altered as fights usually occur when bunnies reach puberty. If they are already altered and bonded then ignore all that!
For bulk hay I’ve found the best prices to be from local feed stores. So I would suggest checking out what you have available in your area. You just want to make sure it’s “horse quality”. If your’e a bit allergic I would suggest trying Orchard Hay. My husband is VERY allergic to Timothy hay but Orchard doesn’t bother him. I keep my bales in plastic tote bins with drilled holes in them for airflow/mold prevention.
And finally on to dogs! For dogs and bunnies to interact the dog must have at least basic obedience training under their belt (especially a reliable “leave it” and recall). I would discourage playing between them because it’s too easy for injury to occur on accident. They don’t really play the same being prey and predator animals. My dog used to get overly excited around my bunnies so I would have her lay down. It’s kind of funny because now she automatically lays down near them and will even “army crawl” around them. Lol.
Hope some of that helped! 