is 650w psu enough for this build?

Looks good to me as is, faster ram won't be of much, if any, use for 99% of games, and a good majority of other apps. And a 250Gb ssd is fine. That RMx 650 is an excellent choice of psu and will easily power that system, no matter how much you OC it.
 
Thanks a lot boyz for the confirmation about the psu, regarding the ram speed, nah I'm not really into having 2666mhz+ since i5-8600k maximum ram speed is 2666mhz, for the ssd, I don't know, I feel like the new NVmE tech is just great compared to the samsung 850, even with the 500gb, I'm barely using over 100gb, I even feel like 128gb ssd for me is totally enough but 256 and 960 evo is just the right pick for me.
 

Why did you pick seasonic over corsair psu? I feel like the corsair one is more relible, I might be wrong though, need further clarification.
 


Both have a 10 year warranty.
Seasonic is one of the top 2 manufactors of power supplies. Crosair has never made a power supply their just rebrands made for them.

Faster memory for the same or lower price is a no brainer.

Boot time difference in a PCI and SATA SSD is almost nothing. You can get double the space for about the same price or save some money and just get the 250gb version.
 
but what if I like to have some rgb lighting to my case? that''s why it costs more tho isn''t that kind of riught? I get your point, but yeah I just prefer to get a good looking ram over a non noticeable difference specially for my usage ("gaming")