I use Ebay HID kits with great success. The 35 watt HID is about the same as quartz iodide 100 watt, IMO.
HID draw about 2.4 amps when up to operation which is about 1/2 of QI. Pattern in Gen1 is just fine, IMO. Despite all the cut and paste arguments as to pattern and glare, I've installed....30+... something like that, into H4 headlight buckets and everyone is happy.
Cost off Ebay ~$20.00. Make certain that you buy the style which has it's own separate power supply with relay unless your system has already had conventional headlight relays installed. HID can pull over 15 amps for a very short time during start up which can be hard on OEM wiring and switches.
Here's an example of the harness type which has the relay: HID Motorcycle Xenon Conversion Harness Fuse Relay Wiring H4 3 HB2 9003 H L GBNG | eBay
I'm still not sold on LED because the cost continues to be several times that of HID and the claimed performance does not reflect the additional price. The other issue I have with LED is the need for the bulky fan with its need for ventillation.
In the case of restricted space, best to select a bulb with the small sized base, IMO.
I've had great service from this type of ballast: VS2 35W Wireless HID Xenon DC Ballast Discharge System for H1 H3 H7 H8 H13 | eBay
But this type do not have potting inside the module and have had three fail now so no longer will accept them: HID Bi Xenon Conversion Kit Slim Digital Ballast Dual Beam H4 3 H13 Hi Low 6000K | eBay
There are several colors of labels but all I have seen with this butterfly shaped label are not potted internally.
The bulbs shown here are fine but the bulky magnet in the base means having to slice the bulb boot to fit which isn't a big deal excepting for tight spaces.
This type of bulb is nice for space but the ballast and bulb color are not suitable, IMO.