Another AV Cupboard HDMI matrix Question

spaceHopper

OK I'm in the middle of an extension to the house and the architect speced an AV Cupboard, thing is they expect me the spec what goes into it and although I'm an electronics engineer I've never had to do this. Added to this is that building extension is expensive and we've no budget for this so it has to be cheap and simple, if I say Raspberry Pi to the wife she thinks recipe book. Below is a rough out line of what I've asked the electrician to do.

The idea is to make it further proof, at some point I'll add 4x4 hdmi matrix to the system with cat 6 between the matrix and terminators, which will send back IR.

I may add a PI to cupboard to control the matrix over RS232 and a smart phone, there are apps for this? I might knock up something simple. For now we will get saoir view and free view sat tv in the living room, Inter net from UPC and possibly have a cheap sat decoder in the front room, aka no UPC TV just internet / phone

We've bought a new smart TV with a sat decoder and sound bar so I don't need 5.1 surround in the living area but I hope to add speakers, two of which have to be ceiling mounted

I'm looking at these kind of matrixes

https://www.tripplite.com/4x4-hdmi-over-cat5-cat6-matrix-splitter-switch-transmitter-video-audio-1920x1200-1080p-60hz~B1264X4/

https://www.monoprice.com/product?c_id=101&cp_id=10113&cs_id=1011310&p_id=8151&seq=1&format=2
Terrible reviews mostly for a poor power supply which is easily fixed


Sources
Remount existing satellite dish (to back wall), drop cables into av cupboard
Drop coax cable from antenna in attic into av cupboard.
Drop two additional coax cables from attic into av cupboard.
Drop UPC cable from back wall into av cupboard.
Run phone line to av cupboard.
Run a door bell to the av cupboard or hall


End Points
Three tv points in plan T20-20A,
Open plan living area, front living room, play room.
At each of these have two /three coax and two cat6 or better cables.
In the play room add one additional cat 6 network point
Up stairs add one network point in the box room and one in the master bedroom, they share a partition.
Do we need a network cable for the boiler

Speakers for surround sound
Mount two rear speakers in the ceiling in the open plan living area
Mount two front speakers in the wall or ceiling of living area, also mount a front centre speaker, drop a cable for a sub woofers too.
Run cables for these and for a sub woofer back to the av cupboard. Run a second set of (six pairs) cables from the av cupboard to tv point on living area