Streaming + DAC questions. Please help this noob!

Hi Guys,

After a couple of decades avoiding the desire to become an audiophile . . . here I am. I've jumped head first and purchased the following:

Bryston BP 20 preamp
Bryston 4B SST amp
B&W 801 Matrix II

I'm actively avoiding becoming a vinyl collector (too many hobbies, not enough physical space, etc etc), so most of my music will be from Spotify. I know they aren't the greatest quality . . . but for the sake of ease and variety and modernity, that's what I'm using. My 'hub' would be an imac sitting 10 feet away from the hifi system. I'd like to control from that computer since that's where I'm sitting most of the day. 

At first, I had hoped to be able to connect via bluetooth adapter directly into preamp and that sounded horrible. (Lesson #1). I then tried with an Audioquest Beetle and that sounded pretty good. I also tried an ipad direct into the preamp and that's OK, too (not as good as with Beetle). But it's clear to me I probably need a dedicated DAC (Lesson #2). So my questions:

1. Whats the best way to use Spotify connect via my Imac? Should I dedicate the ipad to sit on top of the hifi? I also have an old macbook pro that could sit on the hifi and be the connected hardware. The beetle worked fine, but I don't want my computer sounds to come out of my hifi system, only Spotify. 

2. My head is spinning with DAC info. It seems like I can't go wrong with a $99 Schiit, but I'd rather just buy right the first time. Happy to spend up to 1k (used is definitely ok with me) on a DAC that I can just forget about. Did I mess up by not getting an integrated preamp/dac? 

I come to you guys with humility and ready for Lessons 3 thru infinity.