Hey there, I decided to try mining myself because I found it interesting. Mining wasn't profitable roughly a year ago, but today in January 2018, there is some good returns to be made. Here is my layout of how I am making some fun learning money. I will answer your question after my little explanation. I consider my build an investment and I live alone bearing all expenses myself on near minimum wage. With some money I saved up over several months I have purchased the following;
GTX 1080 Ti x 4
GTX 1060 3gb x 1
Asus ROG Strix Z270F
Intel Celeron G4400
8gb Corsair Veng. DDR4 Ram
256g SSD
2x 1200w PSU's (Calculators said under full load my mining rig would take 1800w power, but with 3 1080 ti's it never tops 750w)
I already own a gaming PC with an i7-7700k and a GTX 1060 3g SC, as well as a very old PC with an i5-2300 and a GTX 750 ti. I tried mining on my gaming PC and found myself making $5ish CAD a day and got excited even more after reading about the history of Bitcoin and its massive growth. I am still a full on newbie mining on Nicehash, but these are my numbers (All in CAD)
Purchased 1080 ti's for $1039.99 each, 3 I bought for mining (One gifted for gaming, I only paid half) setting me back almost $4100 after taxes.
I then purchased a GTX 960 for cheap from a friend, $60.
The rest of the computer for mining cost me $1000 because I spent $350 extra for another PSU and $280 on an expensive motherboard.
So with all my new parts here put together, this is what I had running in total with even my old computer running.
GTX 1080 ti = $12.75 on average per card, per day. Some days they've made $14.75 a day, sometimes $11.
GTX 1060 3gb = $4.00-$5.10 per card per day.
1080 Ti x 4 = $51/day
1060 3gb x 2 = $8.50/day
960 x 1 = $2.15/day
750 Ti x1 = $1.05/day
Total: Close to $63/day, especially over that with my i7-7700k making a couple bucks a day. Depending on the day this can go up or down $5 or so a day, these numbers are for a fairly decent day. Now I understand you may not have old computers and spare GPU's to mine with, so this is probably what you need to hear. With my initial investment of around $5100 CAD ($4080 USD) I pull $51 CAD a day ($1530/month) or $41 USD (1225/month). This means I have an ROI of 3.5 months before the rig is paid off and i'm left with high amounts of profit (Seems probable) and cards with very high resale value if I ever wish to pull out.
If you read my math, thanks. If you just want a 1080 ti recommendation, here it is.
Just about ALL 1080 ti's are sold out worldwide. The only places i've found some that are slightly overpriced are on the amazon page of Japan. Everywhere else runs around $1500 per. This is part of the reason I am about to say this. Buy any cheap 1080 ti you can find. Period. Hashrates and cooling can differ from card to card but not enough to justify paying more (Except MAYBE a water block card). I personally own 4x Asus ROG Strix cards which run very cool when at 80% power with +110 core and +500 mem clock. Just find the cheapest 1080 ti card you can get when stores start getting them back in stock. I suggest you move quickly when buying them as they sold out because of us miners finding out they are getting really popular + profitable.
Your CPU won't matter at all, as long as it can run the mining software. A Celeron is more than capable.
An SSD is a wise choice as while tuning you will have plenty of restarts and booting in 7 seconds instead of 27 seconds will save lots of headache. You will not need to purchase Win10 to run your mining rigs, you can run Windows 10 for free by not activating it. I considered getting Windows 10 Pro for the remote connection feature, but I found the Chrome Remote Desktop application to be much easier to use as there is a phone app that is very responsive and I can check on all my computers while at work or on the go.
I have sloppy writing, but I hope I was able to help you.