Hello. I have been away from this forum for 1 1/2 years, so i don't know what happened, but the forum seems much less active than it was. I don't have Ryzen yet (i have it on order), but my 2 cents, in case you get no other replies and you want a half-decent advice in short time:
Considering you want to overclock in the future, i would grab a X470 motherboard, of those with >4 phases:
Don't get a 4 phase one, it won't have much overclocking headroom for a 2700x. Look at the "echte Phasen" column. Where you see for example (4x2), it means, they are 4 phases, doubled (using a doubler). This is better than 4 without doubler, but in general, 5 or 6 pure phases might be better, although it depends on the mosfets used in each motherboard. Personally, i 'd go either MSI X470 (has usually good heatsinks) or ASUS X470. Go to their websites, find a model you like and with heatsinks that give a lot of surface, check also the "AMD motherboard" section of the forum if there is a specific discussion about it, to make sure it has no weird bugs and go ahead.
About RAM, the "gold standard" for Ryzen is RAM with Samsung b die, 3200Mhz. Usually such RAM kits are sold as 3200C14 (or 3200CAS14). Non Samsung RAM will work too though nowdays. I suggest you control your motherboard's QVL list to make sure you can use the RAM you will pick. Some kits, are certified to be used with all 4 RAM slots occupied (so you can install later another 16GB kit, for a total of 32GB). But most, aren't. Which means you will be either stuck with 2 RAM sticks or you will be able to run 4 sticks, but not at the rated frequency. Ryzen likes high frequency memory. So don't drop below 3000Mhz, which is the fastest RAM speed supported by Ryzen 2nd gen (2933Mhz effective speed). Myself, i ordered Corsair CMK16GX4M2B3000C15 (3000Mhz is not ideal, but it's a good compromise), because it's not insanely priced and on the MSI B450 motherboard i ordered, it is supported in all 4 slots (so, in the future, i may even run 32GB in 4 slots). You want to buy 2x8GB kit nowdays. Don't buy 1x16GB, because you will lose dual channel.
Hopefully, someone else will give you more direct advice. The above is a general purchase guideline. Bottom line:
- Motherboard: The more phases, the better for overclock.
- RAM: Higher speed and lower latency (latency is the "CAS" or "C" part you see on the RAM kits names) are better, but check the motherboard's QVL (find the motherboard model and check the supported RAM section) to make sure it's supported and in how many slots (if you don't plan to ever run more than 16GB, 2 slots are enough. If not, you need a RAM kit that will be supported in 4 slots on your motherboard). An example of timings you may find in RAM kits spec sheets, is "15-17-17-35". The first, is the most important, the CAS latency (15 in this case). The lower all these numbers are, the better. If you can get 3200Mhz C14, that's ideal. But they usually charge accordingly.
- Double check the motherboard model in the "AMD Motherboards" section, to see if it has some well known defect. For instance, it is probable, that in MSI, when overclocking, you lose power saving features, from what i 've read. In case this is important for you, i would probably go ASUS or Gigabyte first.