Dynaudio Home Theater set up

This is the deal, I currently own the Dynaudio Contour S3.4 speakers. The question I have would the Dyn's Contour 1.3II or 1.3S work as rear channels with the Contour S3.4 and I will be using one of the contour center channels as well.
I know that the Contour S1.4 would work great but they are still very expensive and are still hard to get used.
The amp I’m using is a 7 channel Krell showcase with a Showcase processor as well.
The last thing is I'm moving to the UK in September and the average room size is smaller than what’s here in the US so I still need to take that in to consideration as well.

Thanks for any advice

The rear speakers are not as important as the front 3. You may want to look at 1.8mk2's for the rears. My system is going to have 4 Contour 3.0 and a T2.1 center. I think you will be just fine with almost any Dyn speakers for rear surrounds.

Rear speaker choices will depend a lot on placement. If you have to place them against a wall, you will most likely have to plug the rear port so it will not be boomy. So that will automatica change the tonal balance of book shelve type Dynaudio speaker by a lot. Might not be worth spending so much money. Even a pair of Dynaudio Audience 42W with front port will sound better.