HD Cable converter w/ phone link

[OwenRichmond]

Hello,
I have a comcast converter from cable to phone and computer. It is a rental for $3.00 a month. I also have a box that converts hd into analog for a $1.00 a month with the second one costing $6.99 a month. At Best Buy they have a cable to computer modem for $79.99, no phone converters except Vontage. Is the model that Comcast rents available for purchase?
The VHS recorder/player I have accepts analog cable and allows one to record a show while watching another, now with the cable converter you can only record what you are watching unless you pay the cable service for their package. I prefer to own a device that may last 10 years or longer, rather than to rent equipment that will never stop costing rental fees. Are there new DVD or VHS recorder/players that have a built in HD receiver? And will they convert to analog? or do I need to buy a new HD TV to use a new DVD/VHS device?
Thank you in advance for your time,
Owen