In my opinion your ride is a "bit off" in a sense that it is MPV. What I meant is that you will need to factor other things as well such as ride height, load etc. What I experienced when I first installed bbk on the front is that it feels like my car have too much stopping power and I can feel that I'm being thrown to the front yet it feels that the rear are still "playing up". I did some research before finally finding the mate at the rear that makes me happy. Not sure if it's just me or there are some actual theories to backed this up but merely sharing what I feel. So if it is actually holds true then you need to get both front and rear researched and done as otherwise you may feel that the car is throwing to the front but yours would have bigger impact since ride height is a lot greater.
In terms of common stuff like pads, if you do get not common brakes then what you can do is always have one spare set at home. That's what I did.
BBK might not always be the case. Some actually changed to a better pads and some changed to better/bigger/featureristic (I made that word up, means the disc have features like slotted etc) disc. These do play pivotal role in your stopping quest. Some instead of getting a BBK which can be costly, you may just get a really good caliper to mate with your existing disc/rotor.
Don't have any clue what rims you are running now but check if the BBK fits in there. Size and offset of rim matters for clearance depending on BBK