Starting a second system, need efficient speaker suggestions.

He's an 8hr drive from me. Maybe later this year when the wife is off for the summer.

. . . for more on the triode versus ultralinear subject, I did a search on this site (using that as a search engine). The results were like every other audio subject/debate here: no 100% consensus. As I typed previously, it’s easy to go back & forth and decide for yourself, but I can see your point--if you are selecting speakers based on which setting you’d like to use , I guess you’d probably like to have an idea what each setting will do for you (before you buy the speakers). Anyway, here are the search results I found in case you are interested in what others on the site had to say about the subject:

@traudio wrote:

... Current speakers are Magnepan 3.7i with a Hegel H390 integrated. 

I'd like to try the other side of the audio coin, tubes and higher sensitivity speakers.

Those are very capable main speakers that you currently have. If you want to try the combo of tubes and high efficiency speakers that's somehow a "from the other side of the fence"-equivalent, and one that emulates the sheer physical height of overall large air radiation area of your Magnepan's, I'd go for some large, "old school" and used horn speakers the likes of which could be a pair of older Klipsch Khorns (that also have upgrade kits for the mids and tweeter section by Greg Roberts) or other similar-ish. Disregard new speakers - with $4-5K perhaps at your disposal I'd squeeze out the most of that dough with used horn speakers that maximizes the physical wallop. We're not speaking blow-your-head-off SPL potential here, but one that takes a fuller advantage of horns in providing for a large, relaxed and dynamically realistic sphere of sound. Indeed, go big, and let that physical framework be a reference or foundation of sorts for further refinement. 

@elliottbnewcombjr , here is another pair of B&W 805Ns on ebay; the high bid is $980 right now & bidding ends in about 3 hours:

+1 Volti - clean, clear, highly efficient.  Heard the Razz at 2 major audio shows - sounded fantastic. I own the Rival.

For 40wpc triod, you’ll need an efficient to highly efficient speakers, and for the budget of 4K, very few choices.  Klipsch Heritage speakers are a common choice, but I believe Volti to be sonically superior