Dvd-ram

For the life of me I cannot figure out what freakin DVD-RAM discs/“caddy” I need to buy for my Hitachi DZ MV230A. The owner’s manual says it can use DVD-RAM ver. 2.1 (8cm) or DVD-R ver. 2.0 (8cm). I just can’t seem to find any true acurate information. I’m thinking that these original DVD-RAM had to have been updated rather than outdated. I don’t know if it is basically impossible to get what I need, or if I’m just looking in the wrong spots. The owner’s manual also states that you cannot use DVD-RAM Ver. 1.0 (2.6G), DVD-R Ver. 1.0 (3.9G), DVD-R for Authoring Ver. 2.0 (4.7G), DVD+R/RW, DVD-RW. Can someone help me figure out what I’m supposed to use, if the ones I need are maybe just replaced by a different/newer version or something.

According to a manual you can use DVD-RAM, which is recordable and erasable disc, or DVD-R, which is just recordable one and has to be finalized at the end, to be able to play in DVD player or a computer player.
All of them are small 8cm disc, not regular DVD (12cm diameter).
You cannot use large capacity 3.9 or 4.7GB disc or in case of DVD-RAM 2.6GB, also no DVD+ or - RW.