Seconded.I'd really reconsider the vinyl thing unless you have a fairly large existing vinyl collection that might not be able to be found digitally.....
I have a vinyl set up but only because I have an emotionally relevant collection of vinyl from my life history. If you don't have similar, then buying turntables, preamps and in particular the music itself is just an expensive way to enjoy lower quality audio.
Regarding your DAC - this does not need to be expensive. You can get an audibly perfect DAC for around $100 - though I'd suggest spending a little more to get one with balanced outputs (since your speakers have balanced in) which should eliminate risk of ground loop noise.
Cheapest of these I know is the Topping D10 balanced at $140. However this only has USB Input, no optical or coax digital.
Going up to around £200 will get you a balanced output dac with 3 digital inputs (USB, Toslink, Coax) which you can use to select different sources.