Flex wiring

[smalltown]

Looking suggestions on wiring up a hanging heater, and air compressor.
My intention is to install a work box not sure what size I need (1 gang or 2).
near each unit (on the wall for the compressor, and on the ceiling) and run some kind of flex conduit to them.
Since I will be running a ground wire to each of them I guess it doesn't matter if they are metallic or not.

What I have seen so far is http://www.homedepot.com/p/Southwire-8-ft-12-2-CU-Modular-Assembly-MC-AL-Quick-Cable-56482101/204804401

I thought they had 6' lenghts in store, but not on line so I'll need to recheck.
Going to wire both with 12 ga THHN wire.

Looks like these premade pieces would just snap into the work boxes, back of heater, and into compressor pressure switch housing.

 

[pattenp]

nonmetallic A/C whips come in 6ft.

 

[smalltown]

pattenp thanks. I just looked on line and found this. I like it. http://www.homedepot.com/p/AFC-Cable-Systems-Liquidtite-1-2-in-x-6-ft-AC-Whip-8015-HD/202286686

 

[wyliesdiesels]

What is the HP rating of the compressor?

 

[smalltown]

Wiley it's one of those that are marked SPL. I was thinking a 20 AMP breaker or possibly a 30 if it nuisance trips. Owners manual calls for 20 Amps ckt. Also toying with the idea of wiring with 10 ga THHN instead of 12 ga THHN after the non metallic whip pattenp had suggested is available in either 10 and 12 ga THHN.
It's a not a portable compressor, but a 60 gallon standing model.

 

[Ainsley]

I like liquid tight conduit I prefer the metallic stuff which is kinda like BX with a rubber jacket. You still have to run a ground through it, and keep the lengths under 3 feet.
For fittings I'm partial to crouse and hinds.

 

[zmaxmotorsports]

You can get 4' seal tight whips also,or just cut them down to length.