Widesliders has a bit of an install process, did you follow it? I remember having to run things with the wideslider patches in order to get them to work. If you did that and nothing happened, uh... I donno. I thought the fikku version was up to date with the one that's floating around out there, and that's the only thing I can think of.
I don't know about a site anymore. Hongfire used to be good about it, but not only did people fall off of it as it started to become unstable, it's now gone. There's supposedly some Chinese sites too, but I've never been able to get my dumb head around them and I think they require you to have a chinese mainland based e-mail or phone number. But if you're on discord there's an amazing discord channel:
Join the Illusion Soft Discord Server!
There you'll find more mods than you probably know what to do with, because that's why my abdata is hilariously huge.
Speaking of mods: for the incredibly ambitious among us
Timeline is here, which is a way to make custom animations. There's been mods like this before, but I didn't know how they worked and they were abandoned pretty quickly. This modder, Joan, seems to have made their mission to turn these illusion games into intros to 3d rendering, so I bet he won't give up on it or make it weird.