Tons of advice. First off being have you ever even played a video game? If so what kind, in a game what matters to you? Are you sure it's those specific things that matter? As for your wife, when you say editing photos and video what do you mean? Is she looking for something that has a touch screen, can be used as a drawing tablet/monitor, is this her profession in life and she needs high end performance or is it something she does for instagram and it's just applying filters and such...?
When it comes to gaming on PC specifically in building one there's a lot that goes into factoring for it.
6. Upgrade ability
To simply name a few. All of which can be broken down to dozens if not hundreds of sub categories. If you're at a cross road of a PC and laptop, then I'd recommend thinking of the following.
1. What is your exact dead max price you're willing to spend?
2. Does mobility factor so much for you that you'd be more inclined for a laptop over something like a small form factor PC (Corsair One)
3. Would you rather have a decent laptop and a decent PC (depending on price range this is very possible to accomplish.)
4. What kind of games do you play, how do you play those games (competitively or for fun), do you care about resolution (1080p, 1440p, 4k) or FPS (60Hz, 120Hz, 144Hz, 240Hz), or is it just the things you can do PC wise versus console like Skyrim Mods, MMORPGS, etc.
5. Between you and your wife who actually requires mobility out of a PC and would one be happier with a laptop over a PC?