Do I need M42 AF Confirm Adapter?

Hello guys!
I have some questions.
I have Nikon D7000 and want to start using m42 lenses. I will buy Takumar SMC 1.4 50mm soon.
At the moment i'm looking for Nikon M42 adapter and I know that it needs to have the glass that allows focusing to infinity.
I also heard for AF Confirm chip that comes with some M42 adapters.

My question is, do I need m42 adapter with AF Confirm chip and what does it do? I will be using m42 lenses for filming. I don't know if I should get adapter with glass only or adapter + glass + AF confirm chip.

Side question:
What are some great and affordable m42 lenses for filming?

P.S: It saddens me that Nikon didn't release 1920 x 1080 25 fps / PAL. I'm European and I need 25 fps here and 1080p doesn't allow it Any news on this situation?

I have Helios 58mm f2 and I am using the cheapest adapter you can find on eBay, and it works of course, but it can focus to maybe 3 meters, nothing further.
Focus confirmation light works well, it is not a CPU lens so you need to enter manually the focal length and f number for Non CPU Lenses option in menu.

As for good M42 lenses, I thought about it some time a go, but for what I am photographing I need something different, so I gave up.
You can find cheap Helios lenses, I bought my with Zenit 12XP for $10, but the quality is not at all reflected in the price.
I can send you some photos made with that lens so you can see for your self...