I just made account on this forum, and want to say high to everybody. Also i want to ask for some help / advice straight away

My problem is with sign up to Factorio.com, i planned to buy the game here, directly on website (and maybe later connecting it with Steam, i found in FAQ that it is possible),
but apparently it turns out that there are two kinds of accounts, one for forums, and one for Factorio.com.
So i proceeded to sign up there as well, the problem i face is, when i try to go to next step it says my email adress is used. Well, that is true becouse i just used it for forums.
So, my question is, do i need to have 2 emails? Different one for forums, and different one for main site? I don't want to be split like that. Especially if i'm going to pay for something. I also don't want to write / remember two sets of passwords or credentials. I would totally prefer to have these both things under one email. If there is anything that can be done about that i would be very grateful.
Big thanks!