Now none of that is Tome material. My "Tomes, Demons, and Darkness" PDF is almost entirely Tome material with a smattering of SRD stuff here or there (classes mostly). It's all the essays and crap and some sections that are just outlines of what needs to be filled in later. It's 265 pages. I have one picture in my PDF, and the SRD has none. So you're at like 1,050 pages pre-art. After Sundown was about 204 or 206 pages before any art was put into it, and then it's up to 224 pages right now, so Art sprinkled all about is adding maybe 10% to the size of things. So, you'll end up with maybe a 1,100 to 1,250 page document all said and done.
Wrong as a wrong thing. To make it all work together you have to go through and line-edit every single monster, spell, item, and anything else to adjust stats and update it to the new system. Even if no changes are needed, you need to look at the rule-segment in question and then determine that no changes are needed.The Monsters and Items are already written up though! you don't have to write them again!
I've done PDFs for The Ends Of The Matrix (100%) and After Sundown (95% done, still working on that one). I've tried several times to put "dnd 3 into a single PDF", First I tried with all of 3.5 + Tome grafting, then 8 months later I tried for a while with JUST 3.5 and no changes at all, and then 8 months after that I even tried e6 + Tome just to cut down on the content count of what I'd have to put in and be "complete". There is just so much content to go through no matter what you do, it's absurd. Maybe it's less absurd if there's a dedicated team, maybe.
I don't want to break your spirit, but just know what you're signing up to do.