Hard to go wrong with any of the options, so yes, they’d go well together. What’s important is satisfying your ears and budget. 

Thanks, im not looking for something super loud, just want that bit of extra bass for tv and movies. 

Sonos’ recommendation, I believe, is Sub with Arc Ultra. 
 

What are the recommended products to pair with Sub Mini?

For the best experience, pair Sub Mini with Beam*, Ray, Era 100, One*, One SL, or an IKEA SYMFONISK speaker. Sub Mini is also recommended for smaller bookshelf speakers powered by Amp.

It is recommended like this post above but I think the Sub Mini is enough if you don't want a excess of bass and only fill the frequencies remaining :)

Thanks, would you say the surrounds or the sub should be added to the Ultra first?

I think the surrounds because it will make your content more spatial and having the notion that you don't love very much the bass (only the essential) for me this is a better decision. :)

Thanks   assume era 300s the better option there?

Yes, for the most inmersive audio, if you play much dolby atmos is good if you most play 5.1, 7.1, etc. (Not Atmos) I recommend more the Era 100 or rarely the fives

ERA 100s definitely smaller footprint! If theres not a huge drop off from 300s I might look at those 

Also the Era 300 need 30cm (12in) extra for each side and the Era 100 only 5cm (2in) :)

Think you've just helped to make my mind up, thanks pal

Hmm...not sure why your post has been marked with best answer regarding surrounds given your post was about Subs? I only mention that because if you still have a question about Subs members may not bother to contribute assuming you’ve gotten the answer you needed. However, I’ll submit my thoughts anyway.

I prefer to think about Subs in terms of low-end frequency reproduction vs bass. Here’s why…

The human ear has a range between 20GHz to 20,000Hz. The number on the left reflects the low frequencies.

The average audio recording for music is between 80Hz and 15,000Hz.  80Hz is nowhere near the low frequency of 20Hz. Therefore, to get lower frequencies for music they must be artificially manipulated by the listener. Ergo, “turn up the bass” for more “thump”.  IMO, a Sub-Mini would most likely suffice.

For movies IMO it’s not so much about the “thump” but more so about reproducing the low-end frequencies found in sound effects (i.e. explosions and the like). I like to feel those explosions without having to manipulate the Sub-woofer. There is where the Sub 3 (IMO) would be a better choice.

If you are 50/50 music vs movies, I’d go with the Sub 3. If the split leans more toward music, then seriously consider the sub-mini.

However, as has been said you have to satisfy your ears and your budget.

Sorry I'm new to this and didn't mean to mark it as best answer, I just wanted to like the post! Ive unmarked as best answer.

Thanks for your reply, much appreciated

I have used both 300s and 100s with my Arc Ultra and for stereo or 5.1 there is little difference to my ears. For Atmos the 300s are a very noticeable step up.

If you do Atmos, if at all posible go with the 300s if you can get them placed anywhere near right, perfect is great but close still sounds very good.

Thanks, would the sub mini work in this setup?

The mini-Sub would work but that is not the question you should be asking. A garden hose will work to fill an inflatable kiddy pool or an Olympic sized one. Same with Subs, do you want a little bit of sub that adds some to the low end or do you want to fill the room?

Your room mentioned, but not many details sounds like a mini might be enough. If the roo. Is open to other rooms, too tall or other condition that reduces low frequency impact it may be marginal. A single full Sub on the other hand should fill that space effortlessly. 

I have two setups in 10x10 foot rooms, Paired 300s and a Beam One TV set, both have full Subs and I have no regrets.