Just as an update, I did some more research and I've ordered the OEM studs from a dealer around me, the ARP studs from the Solstice Performance book (will likely return) and the ARP Miata studs with the flat part. I'll leave a description of what the repair was like when it's all done!
OK, two wheel studs are replaced!
I have a few observations which could be helpful for others:
-I got the OEM studs (9596978) from the local Buick dealer on 24 hours notice. Not bad, besides the price! They are just like the original ones, e.g. terrible quality.
-I didn't even try the ARP studs in the Solstice Performance Book (ARP 100-7702) because they were very similar to the Miata studs but would have required grinding.
-The Miata studs (ARP 100-7720) seem like the perfect solution! Unlike the OEM studs, they are extremely high quality. Unfortunately, they are too long to get in the hole (that's what she said) without taking the hub off of the axle. Which brings us to...
-It was quite difficult to get the old studs out and the new ones in with the dust shield in place. I removed the three 15mm hub bolts, but the shield/hub wouldn't budge, probably due to age and road salt, so I ended up taking my BFH to the shield to create some room, which worked well enough to get the OEM studs in. Next time, I guess I will get a giant 35mm axle nut head and an axle nut and just take the hubs off, then bash on the studs with the hub in a vise.
-I used a tie rod puller to get the studs out but frankly the old, rusted-on studs wouldn't budge at first without some encouragement from the BFH. I tried to be soft with in given the advice to avoid damaging the bearings.
All-in-all, besides having to return a S-ton of parts, it was pretty straightforward. 4/10 difficulty!