Please recommend speakers

FYI, rear ported speakers usually don't sound as good when placed up against the back wall.   Decades ago, before there were so many high powered amps, speakers were more sensitive.   Nowadays, with few exceptions, most speakers are ported and rather insensitive.  Take a look at the KLH product line.

Definitely no on Tekton and I’m not a fan of Polk either. +1 for Klipsch and Monitor Silver. Have you thought about a used pair of JBL’s? PS. KLH makes some very good speakers too.

Thanks everyone! So here’s the final list in approximate ranked order from most to least likely, though I haven’t entirely decided yet. I need to spend some time browsing the used ads on a regular basis to familiarize myself with what is out there especially the brands with which I am not familiar. Certainly the less risky approach is to go with a brand that is well known and respected, and given my general approach to things, this is likely the path I will take, at least until I learn a lot more about high-end audio. But I also respect what the smaller companies are trying to do and recognize there is potentially great value being offered. I know it’s not easy competing with the big brands with huge marketing budgets. I appreciate all the advice and recs, and the lively debate that has opened my eyes a bit to the world of high-end audio. Without further ado, here’s my final rank list:

1) Klipsch 600M (new) - high efficiency so good match for my 50wpc amp, good for detail, good reputation

2) Monitor Bronze (new) or Monitor Silver (used) - good reputation, detail, appreciate the design

3) Original KEF LS50 (used) - excellent reputation, detail, risk of purchasing used speaker that is several years old

4) Wharfedale Diamond - excellent reputation for value, warm sound will balance the SMSL SU-9 DAC, but will likely be looking at Wharfedale for floorstanders in the future and want to have a contrasting pair of bookshelf speakers for more technical listening

5) Wharfedale EVO 4 - could be the dark horse here, need to look into this some more, curious about the AMT tweeter

I would not worry too much about purchasing used.  I have built two systems that make me very happy purchasing used.   If you can make local purchases, even better.  If not,ask lots of questions,and ask for lots of pictures.  Enjoy your journey! 

There are so many reviews on Youtube, Stereophile and several other sources on the budget bookshelf by experts with good ears.  I think you should do your own homework.