I forgot to mention that I am growing this mango from seed! Hence the questions about grafting.

Generally, if you want a particular variety of mango you graft it onto a mango root stock that copes well with the soil conditions and is able to support strong growth in the graft. The graft produces the fruit you want. Also, the graft is usually taken from an advanced tree and so is effectively as old as the parent tree. This means it can produce fruit without any wait for maturity which can be a number of years for a seedling. I don't know what Kent are like as root stock but you need to find a mature tree to get your graft from. There's plenty of instructions how to carry out grafting on youtube that you can search out.

Is grafting necessary, I know it will not be true to parent but is there a good chance the fruit will still taste good? Maybe even a brand new variety of delicious mango?

Also, I have checked with local nurseries and they do not sell scion for grafting. I do not have any friends with mango trees. Do you know of any places in southeast Florida or online where I could buy them at lower quantities?

I'm not in the US so can't advise on scion sources there. If your mango grows up it should eventually flower and fruit. But for seedlings that can take 8 or more years. Your tree might produce superior quality fruit, or maybe very poor quality, or anything in between. But it will take you a long time to find out which you have. In a way I was fortunate in that the previous owner of my place developed a variety of Mango which he said was excellent. He wouldn't tell me which tree it was, said he was planning on coming back later and getting it. There were about 600 Mangos on the place but I managed to work out which it was.

Mangos typically fruit in four to five years from seed-sprouting, if growing well. The advantages of growing from seed are stronger faster growth. And so, give it a go, see how it's fruiting qualitiy is,... if it's good,... then good,... if not, it can be grafted, and will grow more vigorously when grafted at the later established time, the graft growth will grow more vigorously given the established root system.