Suitable bicycle grease for aluminium and steel materials? I hope you enjoy your day.

A few days after of using my bike I have some troubling feeling about it. I can hear a cracking sound or something similar, and on the internet I found out the cause.

I concluded and was hoping that the problem is only the seatpost.
But I've found another one. When I pedal, the bike also create a cracking sound, especially when pedalling too hard. I hope that with a little bit of cleaning and lubrication I would be able to fix that.

But sadly again, sometimes I also hear the sound when I brake too hard.
I hope it's gone.
For now, my seatpost is slipping when I seat on it.

My questions is: since my bike frame is made of an aluminium, what kind of grease should I use?
In the shop that I visited only "Ceramic" or "Teflon" were available. Which one is most suitable? Please remember that my frame is aluminium and the seatpost is steel.

Which grease is suitable for two different materials, in my case aluminium and steel?

I found those on the internet and they are available in my local bike shop:


http://www.finishlineusa.com/products/bicycle-greases/ceramic-grease-advanced-bearing-lubrication
http://www.finishlineusa.com/products/bicycle-greases/premium-grease-made-with-teflon-fluoropolymer


Little hard to find:  


https://www.parktool.com/product/anti-seize-compound-asc-1


Which priorities should I take into consideration given the choices above?

Thanks
After thinking longer about feeling unwell. I research little bit longer about what is the suitable grease for seatpost, especially on aluminum material.

I found out on the internet talking about using a grease on the bicycle. In there, they said about do not using the grease on the seatpost because can cause damage on the bicycle. The reason is that grease can make the seatpost slip and must tighten the clamp more and more which can cause bad for the bicycle or cause the crack sound because over tighten on the clamp.

The advice they have given is used like "Assembly Paste", like this product "Anti Seize Assembly Lubricant", which specifically designed for use such as in the seatpost area. Because the cause of problems in seatpost is corrosion, erosion, abrasions, due to large friction which results in changes in size at seatpost, and then makes the other problems such as crack sound and slip. 

Then the result is "Assembly Paste" prevent all the causes, and I will go for it.

The references



                
             

                
            


Thanks to all who have participated. I hope this can be a useful reference.