Everyone wants the 'perfect' diary for them, be it a particular format or a particular layout. Or is it that you would like better quality paper because you are a fountain pen user and you don't like the 'bleed through' you get with the standard offerings.
We have covered alternative suppliers such as Quo Vadis before. However, you might already have a source of that perfect diary available on your PC/Mac in the form of Outlook.
I'm not suggesting that you start keeping your appointments on Outlook and in your Filofax. I'm just suggesting you use Outlook or a similar application to create a blank diary insert covering the period you want.
My previous post last year about using Outlook covered most of the formats available, but you might want to revisit the various options you can select from within the Print Style menu. Day per Page or Day per Two Page are available, as well as weekly and monthly formats. Notes areas either lined or blank areas can be added. In weekly formats you can have vertical formats (Left to Right) or a conventional format (Top to Bottom)
Now selecting paper for your diary, don't forget to check what paper your printer can handle reliably. You need to look at the paper specifications for your printer. Some printers have different paper handling specifications for the manual feed tray compared to the normal paper tray. The figure you are looking for is the range of paper weights which is often quoted in grams per square metre or gsm. The thicker the paper the heavier it will be, but also remember the less pages you will be able to fit in to your Filofax, unfortunately you can't alter the basic physics of this.
You might want to purchase your paper locally, this way you might be able to get some sample sheets of paper to experiment with using your favourite ink pen to check to see that it doesn't smear or bleeds through to the other side. You can get paper similar to the much loved 'Cotton Cream'
If you are printing your own diary you don't have to print the whole year in one print, you can break it down in to each month, change the colour of the paper even for each month, use tabbed month dividers without the usual problems associated with Filofax diary inserts. You can also print mixed formats to cover the year, say three months of day per page format, then say weekly formats for 3-6 month range and monthly layouts for 6-12 months, so the closer you get to events the more detail you can include.
You will also need a paper punch and we have covered these in various posts before. Printing A4 or A5 is fairly straight forward, but it is possible to also print your own personal size diary.
I think it's worth experimenting with trying out your own format rather than a preprinted one, you might find something that makes your Filofax work far better for you.