zRinn

You may want to get an i5, just because even though most games will run alright on an i3, because it's not a true quad core games won't perform as well, and CPU demanding games won't run well. i5 is a great "just game" platform.

I don't see anything that would bottleneck your system if you are playing at reasonable settings. However, if you are looking to do any upgrades, consider getting a boot SSD, as it will make your system feel much more responsive.

A power loss will not fry components, and since you said you don't mind losing whatever you're working on, a UPS probably isn't necessary. A good surge protector will do the trick for power inconsistencies. However, it is a good safeguard and extra safety measure so you don't lose those precious components. You should make sure that the UPS has enough battery capacity to run what you plan to have plugged into it for a reasonable amount of time so they can all have time to shut down correctly, save work, etc. You also just want to make sure it has the "creature comforts" you may want as well, like enough outlets, ethernet, and other things of the sorts. You can watch this video here to learn more about what UPS to buy as well.

Since money doesn't seem to be an issue, and you plan on streaming as well, you might as well go for X99 and a 6800k, but the 6700k can definitely handle all of what you mentioned, so you could save some money without sacrificing much performance.

Well why would you want to buy something that is out of the box incompatible with the rest of your parts? He hasn't bought the power supply yet, and what I am saying is that he should find one that is already compatible, to avoid extra work and other issues. Also Sentey power supplies are definitely not the best choice for a new power supply, and he should probably go with a more reputable brand with the appropriate connectors.

To be safe, you should probably find a power supply with the correct cables such out of the box. Using adapters like that usually isn't recommended, especially since you haven't actually bought one yet.

That depends on the resolution you want to play at.

For a 1070 I would recommend 1440p. For a 1080 I would recommend 4k, or you could get an ultrawide (3440x1440) monitor.

If you 're looking for a boot drive, that capacity range is perfect.

A 1070 will crush 1080p gaming at maxed settings, and will generally get above 60fps in most 1400p settings at around high, however mileage will vary depending on the game, and you may have to turn down some settings in the demanding games to get above 60fps.

There will always be issues with SLI compatibility, and if that happens in games you play a lot, performance will take a noticeable hit if the game/resolution is demanding enough. Multi-GPU setups also don't always scale perfectly in most games, if at all.

An 850 EVO would be your best bet for a boot drive.

I would always recommend getting one better performing card over two lesser performing cards, but it all depends on what resolution and detail level you would want to game at. Generally, the 1070 is the 1440p sweet spot, while 1080 and above targets 4k.

Well if he wants it to be a high end PC, buying a processor that's already three years old won't make sense, even if it saves a buck and a half on a motherboard, just because it won't be that high end anymore.

Haha generally they have, if you want one with a good factory overclock and better power delivery than the founders edition, somewhere around $420-$440.