Get two Sonos Fives and set them up as a stereo pair.

Nice but too pricey. Other suggestions?

Get one Five then until funds allow or the room gets smaller.

Seriously though I have a pair of Ones on stands in a similar sized room and they are lost in the space. 

@ericmetzger What is your budget?

A pre-owned pair of Play:5 Gen 2’s. 

Thanks for ur suggestions!

I was hoping to get away with 2 One SLs. 
but is one 5 better?

I like to tie in Alexa to the system. 

Personal preference. Two One SLs will provide better stereo separation, but a single Five is probably Sonos’ best sounding single speaker for music IMO.

And if you don’t already have an Amazon Echo device, you should probably get one Sonos One and One SL.

What about the Sonos Amp? in the UK its £599 then add a pair of cheap second hand speakers. I could find something on eBay for about £30.

Just to add about my Sonos One’s in a 20 x 20 ft room, they are OK for background music but when the family are talking at the dining table you need to turn the volume up a long way to hear the music. Yes they are positioned near the dining table and up on stands and yes Trueplay has been run.

The Sonos five does not have Alexa so you would need to buy one, saying that the Amazon Alexa devices are cheap and 1000% better than the half baked / unable to hear you version built in from Sonos.

Pair of ones and then later add a sub would be my choice. That way you can start small and expand. 
 

fact is the room is too big or the budget is too small to go (new) Sonos without making compromises. Whether that be in time to build and save or in capacity. 

I’ve A-B’d my pair of Play:1’s with my Sonos 5 Gen 2, and the pair was a clear, but not overwhelming winner.  However - my Play:1’s are in a unique position that probably enhances the bass.  I’ve got them inside open-faced kitchen cabinets.

Recommendation:  buy a pair of One SLs from somewhere with a generous return period, set them up in the space, and then play everything you might listen to, from various genres of music to podcasts to movies over Airplay (if that’s a thing you might do.)  See if you like it.  I’m pretty confident that a pair of Ones can play well in that space, but you have to try in your own room - different furniture, flooring, and drapes can all change the sound.