A SSD like the $47 120gb Plextor would be nice but it seems there is no money for it. Dropping to the GTX1050ti makes it cheaper but do look at gaming benchmarks first.
If you stick with just a 1tb drive. Do partition it so the boot drive is either just short of 120gb or 240gb so it's easy later on to mirror it to a new SSD drive. Also the first part of a HDD is the fastest as the drive head reads more data with each rotation vs. the inside of the platters.
It was also called "short stroking" back in the day before SSD's so this greatly lowers the seek time because the drive arm has less distance to travel. The drive will be much slower with one big partition.
Also make a smaller partition at the end big enough for your MP3's and files you just store away so your steam and program folder partition is in the middle so it doesn't use that last really slow part of the platters. Something like 80gb at the end.