Read the forum guidelines
I currently have the Arris TG1682 for my cable modem and telephone modem in one as it is compatible with Cox voice.
I wish to purchase my own modems. What is the comparable equipment that can be purchased that would allow me to have my services? I know there is this link
But can I buy separate internet and telephone modems?
Any stand alone modem or gateway will work since you would be keeping the TG1682 just for phone service. All you would be buying is modem without the phone modem inside. It's up to you if you buy a separate modem and router or a combo unit.
I want to get rid of TG1682. What equipment other standalone equipment is out there for cox voice?
If you want JUST a phone modem, then the main choice Cox gives out is the DPQ3212. You can also use it for internet but that depends on what speed/package you pay for. If it's above 100Mbps, I would suggest getting a different modem too. The best bang for your buck for that modem would be the SB6183.
The only thing from there to decide is which router to buy. Netgear and Asus are the two brands which are most popular. See review site "Smallnetbuilder" for more info.