Hi. I used to own the YRV 1.3 Turbo. Dont come on here much now since I sold it to a fellow enthusiast on here.
Unfortunately I didn't own a 1.0 litre.
For clocks, you might be able to swap this out for a 1.3 litre one. These cars are very easy to take apart. I swapped my turbo auto clocks for one from a mark I/II Sirion auto that had the white dials (1998 to 2005 model) as the yrv and sirion share the same platform. Not saying that the connectors on the 1 litre clocks are the same as a 1.3 litre with rev counter. You'll need to research it from having a look at yours and looking at pictures from Ines being sold on EBay. Word of warning. Swapping the clocks will mean your miles consumed will also be out as the clocks keep mileage. I got lucky as the clocks I bought meant It read 500 miles that I had actually achieved. When it comes to servicing it may mean your readings will be out and you'll get a weird reading in you printouts as I found out.
As for seats. Have done this but by buying seats modified for a Toyota starlet turbo. They were originally out of a Mitsubishi Evo VIIII. And had to cut the fixings from original seats. Have read that some have used Sirion Rally II/IV seats as they are a straight fit. But as I've said before the YRV and Sirion share parts ad fixtures in some aspect.

If you need more then get yourself over to the Daihatsu Enthusiasts Facebook page. BobF is your man for Sirion knowledge. Also DaihatsuDave is the man for parts

Most companies moon things to watch for on the YRV;

- Front and rear sills rot. Had to get mine welded as they failed the MOT

- waterpump can leak due to serpentine belt

- window door switches can snap. Pull out the drivers side and grease em up. The drivers side window controller is essential as it controls the other power window switches in the car.

- spring for the boot door release handle can corrode and snap. Again oil up and grease. If it does break you'll need a whole new boot handle section.

- exhausts if original will rot. Best getting a bespoke stainless system made up.

- wheel arches can get rusty and will need treating

- o2/lambda sensor or sensors will need replacing. Known is e for all Daihatsu models. Last around 40K before you see problems. You might be lucky and only need 1. Some models have 2. One under the bonnet before the manifold. One on the exhaust pipe at the front. Cheap to buy from sparksplugs.co.uk.

Think that's all.

Good luck

Edit:

Have a look at the image gallery on the site under modifications to see what I did with my turbo. It got out of hand at one stage as mine was supposed to be a run a round

Picture of Sirion clocks I fitted to mine are n there think it's page 4? Anyways check it out.