Hi StarCitizens

I have read through a few of the threads here and generally around the net about graphic cards and different specs for running StarCitizen, I apologize if my questions have already been answered I did look around before posting. The whole thing has left me alittle confused and unsure of what to do, Im sure alot of you are experts on this stuff so some of my question will probably seem stupid but i was wondering if any of you could help clear up a couple of things for me :)

PC Specs-
POWER SUPPLY - atx power supply stp 650watt
MOTHERBOARD - asus P8B75-M LX
Ram - 8GB
CPU - Intel(R) Core(TM) i7-3770K CPU @ 3.50GHz
GPU - NVIDIA GeForce GTX 660
Harddrive - 1TB

Budget-
£400-£600
$599-$899

1. From my understanding to play StarCitizen on Maxed settings at close to 60fps im going to need atleast 16gb of RAM and upgrade my GPU to a R9 290X, am I on the right track so far with my current specs?

2. So if im correct on my first question here is where my head starts to spin alittle, with all the talk of 4K and DirectX 12 which I would love to experience, im alittle concerned that I buy the upgrades above and then in a year im left behind again. I did look into this but alot of the info currently seem to be speculation.

3. I see alot of the really high end cards need alot of wattage to run, my psu is 650w unit. I really don't want to have to get another psu and rewire inside of my pc it's all neat as it's how I purchased it. Do you think 650w is not going to be enough going forward.

I understand we don't fully understand StarCitizen yet and exactly what specs will be the best as it is currently in aplha but I want to try and prepare myself and I need to upgrade anyway, StarCItizen does not run very well even on medium for me.

Thanks