Correct cages and cagemates, IMO, are supplies for adequate care of rats. Right now, you do not have a proper cage for your rat, as tanks are not proper cages. A proper cage will be open-air, or made out of metal wiring. Even though you want to get a cage topper that is open-air, the tank is still not. Because it still includes the tank, it would not be considered a proper cage. If I were looking into getting a rat from a breeder, I would be very concerned that the breeder was keeping their rats in tanks. A responsible, ethical breeder would know that rats need open-air cages and not tanks for maintaining good health. (FYI: Tanks do not cause issues only with over-heating. Because there is a lack of ventilation, the pee causes an ammonia build-up which can cause very serious respiratory issues. I kept my very first rat in a tank, and nearly lost him to pneumonia) Remember, any person can put a male and a female anything together and call themselves a breeder. A lot of research into genetics and family backgrounds is required to produce healthy animals. It doesn't sound like your breeder has done their share of research into the proper care of rats.
Also, if this was an ethical, responsible breeder, they would tell you that rats are best kept in pairs and would not consider adopting to you if they knew you were planning on keeping it as a single rat. Even though you say you can provide enough stimulation to substitute yourself for a cagemate, I know that this not possible. Rats are most active at night when you are sleeping so there is 8 hours that you are not spending time with him that could be filled by another rat. You spend 8 hours at high school (EDIT: or work. I was accidentally thinking of another post I read when writing this, and looked back at your original post to see that you never mentioned you were in high school. Still, I will assume that you have a full-time job, which would equate to 8 hours a day being away from home), which turns into 16 hours of alone time for the rat, which only leaves 8 hours of stimulation. If the rat had a cagemate, they would have a full 24 hours of stimulation by another animal, instead of the 8 that you would be able to provide for it. Rats are very intelligent, so 8 hours just isn't enough for them. Think of it this way: Would you want to live alone and only have interaction with another person for only 8 hours a day every day for the rest of your life. Sounds pretty lonely, huh? Lone rats can get very depressed which has shown to cause them to get sicker more easily. There is a very good Youtube video explaining why it is important for the rat to have a cagemate. I will try to find it and post it here for you. EDIT: ThaRatChick was able to find it for me. Please watch it and understand its message.
As for your other supplies, you have the extreme basics, but there are other things that your rat will need. Even with a cagemate, your rat will need other types of stimulation. Chew blocks are a good idea. You state that you have dog ropes. They may or may not be a good idea, because of the numerous threads that could end up wrapping around a limb and cutting off circulation. Maybe someone else could chime in on this issue. Some people on here use bird toys for stimulation. When you get a wire cage, you will probably want to decorate it, so hammocks are a good diea. You can get them at the pet store (made for ferrets) but many people sell them on this forum that are of better quality and cheaper than what you can find in a store.
As was mentioned before, the dog food can or can't be a good thing. It really depends on what brand it is. I tried once to feed all dog food to my rats, and they wouldn't touch it. It depends on the brand and the ingredients if it is suitable for your rats. Many members on here who also run rat rescues sell a very good brand of rat food called Harlan Tekland for about the same price you would pay for dog food in the store. Petsmart carries the brand "Mazuri" which many feel is a good rat block. Some disagree, but it is one of the best in-store options for people who cannot order online or have it shipped. Sometimes you can find the food called Oxbow in stores. That is also a good food, but some rats refuse to eat it (I have one who does). Oxbow can be a hit or miss food. You can order all of these foods online. You can also stick with the dog food, but it should really be supplemented with what is called "Suebee's Mix" which you can find by Google. It is a dietary supplement for dog or rat food for a more complete diet.
Please understand that the people here are only thinking of the rats' best interest and are not trying to be mean to you just because you are new. We really want to help you to have the best set-up for your rats, and a tank and being single isn't the best set-up at all.
