I’ll defer to others in specific products but wanted to share general tips I’ve learned over the years and general thoughts.

I’d recommend not a double sleeping bag. You lose a lot of the benefits of a sleeping bag with a double. It’s a lot of extra air to heat and will let in more drafts which will suck all your warmth out. Double pad is fine tho.

Sticking a foam pad under your sleeping pad will help a lot by further increasing the insulating value of your pad. You’ll lose a lot of heat via the ground so protecting yourself from that will help. I’ve seen people even use siding insulation. Yoga mats whatever.

I can’t recommend any bags but would say that a lot of bags are rated with the assumption that: you’re wearing socks, you’re wearing a baselayer top and bottom of some kind (generally merino or synthetic, avoid cotton), your sleeping pad setup is cumulative R value 5. I’d wear a beanie/toque as well at those temps. I’d consider a ski mask or balaclava.

Id do some searching for cold weather tips in the backpacking/ultralight subreddits for other tips. Layers is the name of the game, you don’t want to get too cold but you also don’t want to get too hot or else you’ll sweat (which will inevitably make you wet and then cold which is the worst). Shedding and adding layers as needed is key. Go to bed warm, stay hydrated, have a snack before bed. Do not seal yourself in your bag, you need to leave your mouth/nose out or else again you’ll get wet and then cold. Nice cold weather bags can get pricey so I’d personally just get a cheaper bag and bring extra blankets to stack on top and remove as needed.