Go ahead and get the rats, will be the best move you ahve ever made.
Can only echo the advice that has already been posted on here. Get 2 rats so they can keep each other company while you are not there. A two level cage with plenty for them to climb and nest in is the best. Carefresh was what we used for the bedding as does not have any odour and is easy to replace.
you will find they pick a certain corner of the cage for their doings. That will need cleaning everyday and you will need to replace the food and water each day too.
When it comes to eating, they are rats and wil eat anyting that they can get in their mouths. There are special rat varieties of food for them. Dont give them (or let them get near) to anything fizzy as a rat cant burp...so will be proper gassed up (they also cant vomit too, so be careful what they are eating).
If you usually leaev old newspapers lying around on the floor, epect these to move on their own and be randomly stripped. Rats love to nest and wil make their own nests out of almost anything. We had a slung hammock that was a good favourite or then an octopus with the legs cut off inside the cage. That ended up full of newspaper, with blocked doors.
Haev only had girl rats, so cant comment on the boys, but from all accounts, the ladies are far more active and will explore more. They are bloody good climbers too, so expect to find them on shelves or elsewhere if left to run.
they are the most socailble and funny pet i have ever had. in fact, would say they are more than pets.
A word of warning, they only have short life spans (2 years norm, 3 at best). they girls are also very prone to gettig mammary tumours, not all of which are malignant, but they can grow to a very large size and restrict the rats movement.
Finally (after a great wall of text) a few pics of the girls