Streamer/DAC - Where is the value?

I currently have ($10K) Olympica Nova II speakers, ($11K) McIntosh MA9000 integrated amp and a (~$1.5K) Cambridge Audio 851N network player. The weak link here seems to be the Cambridge unit. 

I'm prepared to upgrade my streamer/DAC situation and my budget is about $4-6K. Although there are SO many options out there and it's tough to tell where I'll find the most value. My assumption is that the DAC is going to play a much larger part in sound quality than the Streamer. I play music primarily through Tidal. I don't have requirements for server storage or any other sophisticated source capabilities. 

Many of the network players come with a pre-amp which I am assuming I should rule immediately. That pre-amp would be taking a share of the overall budget. On the other hand I was thinking maybe I should buy separates. I could max out the DAC and get something good enough for the streaming. Or even continue to use the Cambridge if I really wanted. Having a beautiful screen on a good looking streamer would be nice but seems like lower priority in terms of bang for buck.

Curious to hear people's thoughts. Are there any specific units anyone would recommend as either an all in one network player or as separates? The Auralic ALTAIR G2.1 seems like the ideal all in one but it's at the very peak of my budget.

Thanks!