converting high def files to iso, or other lossless format

I have some HD files, blu-ray, that I've downloaded in various file formats. I'd like to convert them to .iso's because that's how I have other blu-ray movies stored that I have ripped from disc. I have the following formats:

mkv + par2
.ts + par2
mkv

I have software and can convert mkv's to dvd, but I don't know how to do it for blu-ray. I don't know what par2 files are or how they are converted, with the mkv files, or same for .ts and par2 files.

I have some software that converts HD content (4Media converter, xilisoft HD), but I don't know what format to put them in. I want to play them with power dvd, that's how I use the .iso's I have.

Is it possible to convert these files directly to .iso? or, if not, what do I convert them to?

thanks for any help,
rlr

*edit, also the folders with the multiple mkv or .ts files are divided up into dvd size bits, can I recombine them so I can just watch the movie? I'll be keeping it all on hard disk anyway.
thx