Is there something that does not exist to modify your iPhone to your liking in Cydia? It does not matter, what comes to mind, if you want the numbers of your notifications to appear in Roman numerals instead of as they do right now you just have to install RomanBadge from Cydia.
Comfortable, what is said is not comfortable, but it can be interesting to make your iPhone different and give it a touch of originality.
You can download it free en Cydia.
You need to have done the jailbreak.