lautarolzl :
Well, I think you should provide more info about your needs in the first place. You said a RTX2070 for GPU so I believe budget is not an issue am I right? If true then consider a Quadro as LordVille suggests and pair them with a Xeon or a threatripper CPU. Of course, this means ECC memory sticks but that would be a really really nice workstation (And expensive).
If I got too excited about that and wanna slow down, how about a nice Ryzen 7? It's cheaper than an Intel i9 with almost the same performance and a lot of cores. I'been using an R7 2700X with 16 cores for rendering/3D Modeling and it works like a charm. If you can wait, the 3000 series will be launching soon and it doubles the cores, up to 32 at higher frequencies, Mad!
You can pair it with an RTX2070, they'll work pretty nice together.
Well, the budget is actually right around how much I'm spending right now, which is about $2000. I already have the Ryzen 7 2700X picked out, which was before you asked that, so I'm wondering why you said that? Also, the R7 2700X has 8 Cores. Maybe you were thinking of the 16 Threads? Overall, I think I'm going to stick with the parts I've chosen, but I would like to ask some more questions:
I was wondering if SLI is a good idea, because I may want more power later on.
Also, is it worth the risk of getting a liquid cooler? Because it may spill when I'm changing the water? I'm not even sure if I'm going to overclock so I don't know if I should bother getting a liquid cooler.