There is definitely a measurable impact, sorry article is in finnish but graphs luckily don't care about language... https://www.io-tech.fi/artikkelit/ddr4-muistinopeus-ryzen-2n-suorituskyky/ Of course if that is enough of an impact to justify spending more is a different question and not necessarily one that is easy to answer.
I went with an EVGA 650w modular. I'm sure it's more than I need (although the writing on the Vega 56 box keeps telling me I should have 750w!) but it was a good price and as you say... wiggle room.
Spent far too much on a monitor but it sounds like it ticks all the boxes. Went with an Acer XF270HUA. It's 27" (tick), IPS (tick) and 144hz Freesync (tick). Also according to Trusted Reviews after some calibration they were seeing 0.11 black level, 1127:1 contrast ratio, gamma of 2.21, 100% sRGB coverage and a Delta E of 0.78 so I'm happy it'll split its duties between gaming and photo editing.
Added a Ryzen 5 and mouse mat today so I'm basically done. Need to wait for delivery then I can start building! I still need an external USB3 HDD for backups but that can wait.
I'm up and running with the new PC. Managed to keep the build cost under £1500 which I'm happy with for the spec I manage to get utilising offers, sales and cashback deals. I'm sure the wife thinks I spent less mind you! I haven't built a PC in quite some time, nor overlocked one, so I'm sure there's plenty I've done wrong but it seemed fairly straightforward in the end. The biggest pains were radiator/fan placement and direction debates, bloody motherboard headers for switches, buttons and LEDs and forgetting to pop the M2 in before securing the motherboard (it goes on the rear of the board)! CPU (using Ryzen master) is running 4GHz @1.285v and peaked at 65c after two hours of Prime95. RAM is running at 2933 (1465.7 or something I can't remeber!) and stability seems fine so far. It's a lot quiet than I expected too as a lot of the time the various fans sit doing nothing and even when in a game the noise is more than acceptable. If I could go back and do it again/lessons learned: 1) Maybe re-think the case. It is a lovely thing, truly, but I can't help think it's not very 'micro' after all. 2) Count how many fan headers the motherboard has and order a splitter in advance if needed so you don't waste a day! Doh. 3) Kill the family cat before starting because it will be in everything. PCBuildNoGFX by veato posted 2 Jan 2019 at 11:51 PCBuildGFX by veato posted 2 Jan 2019 at 11:53 Thanks for any advice and help along the way!