are the filter canisters fairly standard? I have to broken ones I need to replace one day? Did they have clear ones?

yes they seem pretty standard and the ones i got were identical to the ones i had before,
the clear purple ones!

I just ordered a DI kit which should be here next week. Where exactly so you connect it in?

im not sure if you're talking about what i ordered lol i just ordered the screw on housings that hold the filter to the unit :)

I ordered a whole new housing and re-fillable DI canister. So I have to plum in the extra canister. I think It goes on the side of the last filter opposite of the t to the output/storage tank. I would think it would go online of the output but it's a bigger hose on that side...