now is not really a good time to buy GPUs brand new, if you can get them used at a good price then fair enough, but making a whole rig of 1070tis/1080tis is costly and wont make you much profit right now!


first things first GPUs for mining altcoins, like a few people mentioned GTX 1070 TI and GTX 1080 TI are pretty much the main dogs for mining altcoins, they can BOTH mine a variety of altcoins, not just 1 coin like most ASICS.

if you want to save power and mine with low watt usage, i recommend 1070TIs, if you dont mind using a little more power in exchange for bigger hashrate, then get 1080TIs.

forgive my rudeness but you dont seem to know much about GPU mining, so the easiest way to start off is to mine with NiceHash, it will automatically select the most profitable altcoins for you to mine and convert them into BTC.
but if you dont want BTC and want to REALLY have those specific altcoins, then you have to download the wallet for specific alt[Suspicious link removed]gle altcoin name + wallet)
follow the instructions.

when i was new to mining this website helped me ALOT : https://thebitcoin.pub/t/bitcoin-beginners-help-start-here-ultimate-guide/27
also reading these forums taught me so much too.

one very important aspect of mining you need to know, you are ALWAYS learning, and you have to read alot and take in alot of information, sometimes you will feel like you dont understand, but dont give up! keep reading and learning and you could understand alot.

if you want to calculate a specific alt[Suspicious link removed]gle altcoin name + profit calculator) whattomine tells you pretty much most of the current coins to mine with value.

as for why calculators giving different results, could be what the other guy mentioned, you using 2 diff hashrates, or entered power usage wrong, i cant think of anything else.

if you want to know WHERE to find mining GPUs check your  Ebay,Amazon,NewEgg or local computer stores either in real life or online via webstore and search for : PC > Components > graphics cards > Nvidia

(btw i mine with nvidia cards so i just use that as i have no knowledge of radeon RX cards >< )

hope this helps