I asked HID Outlet which type I would need if I wanted to keep both Hi and Low in a car that only has one bulb for both. I just wanted to double check. Anyways, this is what I got back.
"You may get either one, it's up to you. Some people who's
vehicles use H/L prefer high and low to be separate bulbs.
But both kits are alright. By the way, what kind of car do you have?
Sincerely,
(Name Removed)
HID Outlet"
So after I got that back I did a quick youtube search for Bi-Xenon installs. Looks like both bulbs are on the same assembly so it shouldn't be an issue that we only have one bulb socket. Looks like this is going to be my next project

I still need to do a bit more research since aftermarket HIDs are new to me. When I figure out which way I'm going to go I'll post it up along with the install info.