If you use the search bar on the right and search new puppy, puppy list, shopping list, you'll find a lot of good stuff. Here's one old post with a list here's another and a super detailed list in the comments.
In response to those lists, I second the no need for puppy pee pads (shibas potty train quickly but do get something to remove the scent if they do pee in the house, nature's secret etc.).
I would add a toothbrush and toothpaste to that list. Get them used to the toothbrush early on even though they'll lose those puppy teeth eventually. Ditto getting them used to the harness.
We never had a play pen and didn't miss one.
I also recommend shopping on amazon for pretty much anything (petco etc. are always far more expensive but we do go to them occasionally with our shiba as a fun outing or to grab a last minute toy or treat).
Start with small bags of treats and not the giant ones in case your pup doesn't like them and since they'll be eating fewer and they might go stale before you finish them. We try to opt for the highest quality ingredients/most natural food and treats which is totally affordable if you hit amazon.
Specific items: Kong zoom groom brush (gentle but works well), midwest life stages crate (grows with dog, durable), traditional kong, kong wobbler (later added a kong genius as well), whatever random stuffed toys you like (still haven't found something that can survive more than a few days with our shiba) for food we used this wellness puppy food which includes salmon and have since graduated to their adult food alternated with costco's salmon dog food.
You'll definitely need something for them to chew (and chew, and chew), ours had some nylabone chew toys but was never interested in them. Loved bully sticks and rawhide though, just be sure again to check the ingredients, you want american unbleached rolls and not the sheets made of lots of little pieces.
Right now she's on wellness because she hated blue buffalo. We spend probably 100 a month in dog food between the canned and kibble (she gets a can a day and a cup and a half of kibble as per the bags instructions). We mixed the two for a while and it worked really really well.
I had the same idea as your wife. To get two different flavors and switch out the two. I've never heard of Orijen though and honestly at this point would be willing to try anything. But I feel like I've wasted so much money on her food. We just bought a brand new 30lb bag of kibble and have used maybe 6 cups of it. I of course threw out the bag thinking she'd eat it.
I think the fact that I'm pregnant exasperates the nervous nellie stuff about her not eating. My hormones get in the way etc. When we eat she gets absolutely no table scrapes for that exact reason. Although I will use string cheese for treats instead of typical dog treats. Do you think that may be hurting me?
Should I just keep trying for a few more days with her Wellness food as I've been typically feeding her?
Edit: This is the kibble we've been feeding her and the canned food.