Built in mics on camera mean no good for audio. Some can be decentbut they will be blown away in general by an outboard solution.
Ok some general info for you, Most mics fall into one of two different categories...
Dynamic or Condenser.
There are otrs but those dont need to be gotten into for this. Dynamic mics are pretty much speakers in reverse, are much sturdier but a little less accurate in their pickup than condensers. Typically you will find them in live stage use a LOT.
Condenser Mics are More Accurate, but require phantom power and arent as sturdy. Phantom Power is a type of power given over the same cable you use for the audio, a 3 Pin XLR to 3 Pin XLR connection most of the time(And pretty much plan on using that type of connection if you are using condensers).
Phantom Power will be listed as a feature on any mic preamp that you look at. Mic Preamps are part of those interfaces you were looking at earlier that takes a Mic signal which is extremly tiny and amplifies it very accurately and quietly to a larger useable signal.
Now all those details out of the way, if you are doing film work and want to be able to do this again using the same equipment, get a shotgun mic. A Shotgun mic is almost always a condenser mic, with a very focused pickup pattern. You will have to keep it pointed at your actor(s) mouth the entire time to get a good signal, and will need a windscreen for it. That is your best solution if you cant do anything involving wires on camera and is what happens most often in film(Look on movie credits for Boom Operators, yea that is the sound guys that get paid to point shotgun mics all day, much more tedious than it sounds trust me
If you can get away with it though a cheaper solution will be a lavalier mic most likely. Shotgun mics arent cheap by any stretch of the imgaination, and a lav you might be able to get a bit cheaper, but will involve running a cord under some clothes and down a pants leg and dragging along the ground. Might not be an option(Usually isnt for film projects).
If you want to get a shotgun mic, I would suggest looking at the AT835 and AT815 shotguns. I dont believe they are that expensive and if you pick the right ones they can be powered via a AA battery inside of them instead of requiring a phantom power interface. You then would probably want to run this into your camera instead of your laptop, and here is why.
Syncing audio and video can be a royal pain in the arse. If you can record it on your camera do it, even if it requires sinking some money into a shotgun mic with a battery power supply on it. This requires your camera have a decent preamp in it, typically most good cameras will have useable preamps(Dedicated seperate ones are better but more expensive) but some consumer cameras really suck in this department.
The AT835b will probably be your better choice between the two I mentioned, it has the tighter pickup pattern and will work better over distances. You will find them around the 250 range though you might be able to find a better price, that is what most places will sell em for probably. The 815 I cant find info on right now for whatever reason, though I used them this summer, had a wider pickup and might be better suited for picking up small groups near you or something to that effect. I actually had to use them for area boundry mics on stage this summer, one screwed up system to make me use those out there.
Anyways hope this helps ya a bit.