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Depends on the time of the year you want to go camping, considering the temperatures will be different.
For your sleeping bag, I recommend looking at the EN 13537 ratings, it's a European standard that rates all sleeping bags equally. It comes with three temperatures, "comfort" above which you're guaranteed comfy, "limit" above which you're comfy as long as you're not too sensitive, and at which you'll be on the verge of getting cold, and "extreme", the temperature at which you only have 6 hours left to live before you die of hypothermia. All of that with no clothing other than underwear.
You'll probably have to check the European websites of companies to access those, because most hide it for all other countries, for it reveals the truth about the efficiency of their sleeping bags, so they prefer to keep bullshitting Americans with inflated performances even if it puts people at risk.
I still remember how a Columbia sleeping bag was rated by manufacturer to be comfy even at -20°C, while the EN 15357 came up with a -6°C extreme temperature, and some guy tested it at -10°C and almost died of hypothermia.
Though you have to know that those ratings show a slight deviation for down sleeping bags past -10°C/14°F, they're a bit warmer than rated, as long as you compensate it with a good sleeping mat.
As for the sleeping pad, it'll depend on your sleeping bag: synthetic ones can be used with foam, down MUST be used with an inflatable mattress. Being highly compressible, down provides no insulation between the ground and your body because you crush it with your weight, unlike synthetic insulation.
Check the R-Value, which indicates how much insulation it provides. I couldn't really tell you what to look for, but let's say that for cold weather at about 5°C/41°F, you need a R-Value of at least 3 for a synthetic sleeping bag, and about 5 for a down sleeping bag. There are better approximations than mine on the interwebs though.
Shit is complex, good luck with that.
