I hope you like it, and that shipping doesn't take too long! In my experience Kevin at Lazer3D is incredibly helpful and responsive (including whipping up a couple of custom top panels for me for quite affordable prices!), but sadly he isn't in control of the shipping companies or customs
My second top panel (with added ventilation for semi-passive cooling + a 140mm fan mount) is currently in covid19-christmas-brexit shipping limbo, in the process of being handed off between various carriers somewhere in Europe. Hopefully it will get here at some point
You being in Canada might actually make shipping smoother than for me here in Sweden, considering the circumstances!
Btw, if you went for one of the wood fronted versions, I'd recommend oiling the wood relatively soon. My HT5 spent a year in storage before I got around to building, and by that time the wood had warped slightly. Not enough to be an issue beyond needing to apply some force when installing it, and not anything that's visible unless you're really close and actively looking for it, but worth looking out for. Some bog-standard benchtop/cutting board mineral oil, or whatever else wood finishing oil (linseed oil, whatever) should work fine. Besides, oiling the wood makes it look better too!
As for power, here's another alternative for you: user TheHack over at sff.network has a business making cases and power supply setups, and makes a custom-designed
12VDC-ATX converter board bundled with the excellent MeanWell RPS-200-12C. I used a different DC-ATX board (from another user on the same forums, GuryHwa/G-Unique), and I'd really recommend that type of setup. It's a bit cheaper than HDPlex, smaller, higher efficiency (the RPS-200-12C delivers >90% efficiency from 20% load and up on 115V, and
MW's detailed testing reports are pure gold for SFF builders), the DC-ATX boards are smaller and run cooler thanks to not needing to convert 19V to 12V, and fits nicely in the HT5. I mounted mine to the right/top of the motherboard, where it fit perfectly, but it should fit fine next to the PCIe slot if that suits you better. I did have to drill two new holes in the PSU's frame and screw it in with some m3 screws and nuts (screws fit through the accessory panel mounting slots in the motherboard tray), but it was a very small, easy and safe mod. You could always just stick it down with double sided tape if you want to.
Oh, and even if you already ordered a Blackridge, another option is the ID-Cooling IS60k (or the lower profile IS-47k, which is the same cooler just with one less fan). There's one drawback with these though: the included mounting hardware has poor pressure, and users have reported much better thermals when mounting it using a Noctua L9i-to-AM4 adapter kit, though that's a bit of a hassle. ID-cooling is reportedly adding a backplate to a new revision of the cooler, but that's not due to arrive for a while still. But if the BR doesn't work for you, at least that's another option to try