I like 1 and 4 but its difficult to say which would go best with the tiling as its so difficult to tell from the pictures. You could also consider shutters .....

For my first roman blind I used a roman blind kit from Dunelm, worked out great. I then used those instructions to go on to make a further 12 (never buy a house with 5 sided bay windows!) and purchased the bits needed from terrysfabrics as mentioned by Catherine Byrne. They are really straightforward. The key is to take your time with your measurements/calculations and with ensuring your edges and rod pockets are straight.

You could look at Clarke & Clarke Waldorf in Champagne https://clarke-clarke.com/product/waldorf-champagne/ https://www.roman-blinds-direct.co.uk/product/clarke--clarke-waldorf-champagne-roman-blind

You will run into problems with child safety legislation using cord and cleat which is why bespoke makers are unlikely to offer this option. Continuous chain (available in a wide range of finishes) are vastly superior as the blinds always raise and lower perfectly. Another option you could consider if budget is not too much of an issue is battery operated remote control.