Whole house setup for sky UK tv channels and freeview

I'm looking for some advice on what to get for a complete home setup.

I currently have a NAS running plex media server. All TVs are smart and have the plex app installed. I'm happy with this. All rooms have 1G wired network.

- I'm looking for a box for the living room that can record one sky channel and watch/pause/rewind another sky channel from my sky dish which has 8-outputs, then i'd like boxes for the bedrooms that can watch sky, live pause, record, rewind etc, but doesn't need to record a 2nd channel at the same time.

It would be really useful if I could press pause on the living room box, and continue watching in the bedroom and vice-versa.

So really my questions are how many S2 inputs does the above boxes need? Is it 2 inputs for the living room and one for each of the bedrooms?

Does freeview come down the S2 cable like with sky boxes?

Can the boxes all record to the NAS rather than internal HDDs? Do the boxes need USB storage for EPG and picons etc or can they use their HDD or the NAS instead?

The boxes i'm looking at, from the sponsor WoS, are:

VU+ Solo SE V2,
Solo 2 Twin

XTrend ET7000 single S2
XTrend ET7500 single or twin S2.

What i'm doing must be a fairly common set up so what would you recommend / what is possible?

Budget is up to £250 absolute max. I was thinking more like £150 - £200. I will get the twin S2 tuner asap and will be buying the singles one at a time as/when the budget allows.

From the above, looks like i'll need some usb sticks which is fine.

Is there any advantage to using a NAS rather than HDDs ? Disk cost is not really an issue as i've a few old drives lying about.
I guess it would make programs i'd like to keep easier to add to plex once they have finished recording rather than setting up ftp or something?

What are your thoughts on the above boxes?