MKV to DVD Authoring Help

Ok I have several MKV files, Some with just single audio video and subs, others with multi video audio and subtitle options, as well as chapters. I'm looking to take these files and make a dvd with custom menus and retain all the video/audio/subs/chapters that are contained in my MKV files, Which software (Paid or free) should I be looking at to accomplish this?

Any help with this would be appreciated. Also are there any software for creating DVD/Blu ray Covers and Disc Art or does everyone basically use Photoshop?

Thanks for Any Help.

Have a look at ConvertXtoDVD. It may not be as flexible as you're hoping for, but it's about the most straightforward method of getting from MKV to DVD (not a very common requirement these days).