I considered both but I wanted to test it out first on a cheap but reliable alternative first. The Alpine HIDs aren't exactly plug and play, you have to drill a hole to a cover or something, I don't remember. It is also the most expensive options of all. LUX seems to be one of the best too and from what I remember, it is plug and play but again, pretty pricey.
This is my next option (http://www.burgertuning.com/BMW_LED_angel_eyes.html), currently on sale at $129 and it uses 4-led. Supposedly it doesn't become dim like the MTecs and comes pretty close to the Alpine and Lux. I'm waiting for others to confirm first to see how it turns out.
Here's the DIY I posted on another forum for changing the AE bulbs. This is for the MTecs and other direct plug and play bulbs w/o any additional harness or cutting of wires. Other bulbs will likely be the same with just an additional step or two. Also keep in mind, I am in the US so the drivers side is on the left side.
First of all, here's the blueprint of the headlight assembly. #6 is the AE bulb.
Step 1: Open the hood and locate the plastic cover for the headlights (circled below). Remove it by twisting it and then just pull.
Step 2: Once the cover is off, locate the bulb (circled below), not very hard to find.
Step 3: To remove the bulb, twist it downward towards the center of the car (to the left from drivers side, to the right of passenger side). There really is only one way you can twist it anyways because the other way is blocked by a screw so you can't make a mistake. Others say you might it doesn't twist easily at times, mine did but if it resist, just a lil force wouldn't hurt. Once you twist it, just slowly pull it and off they go.
Step 4: Remove the OEM bulb by releasing the clips on the side (circled below) of the harness and then replace the new bulb.
Step 5: Place the bulb back the opposite way of how you removed it and you're done.
