Are iPad front covers still available?

Not for current iPads. The internal magnet arrangement that used to once hold the cover magnetically to the edge of the iPad is now being used for other things, such as magnetically attaching the Apple Pencil.

They may still be available for older iPads (you don't mention your model). In that case, if anyone would still be selling them, it would be eBay or Amazon. Apple doesn't support older devices for very long as far as cases & covers go. When devices are discontinued by Apple, usually the cases and covers follow close behind (as far as what Apple has made for the devices).