Piston Conversion Kit Handguards

[scoobydo]

I have been wanting to get a piston conversion kit for my build, but I had a question.
With all the kits, (OPS, Adam Arms, CMMG, Beaver Creek Armory) they all come with hand guards.
Do they come with the hand guards because they are NEEDED to be used with their particular kit for clearance or attachment or whatnot?
OR
Can I use whatever third party hand guard I want?

[whlgun]

Most hand guards will not fit a piston kit.

Magpul hand guards are made to fit now. I find that the lightweight magpul hand guards are great for my Adams arms piston.