I have HID's on every car I own. Wouldn't go without them. GNVenom has had them since 1995. I converted my GN back in 1996 using Philips ballasts and D2S Westinghouse bulbs, with a custom-made shield on each bulb. I used H4 housings made by Bosch. This was high-cost stuff back then. Today, there are much less expensive hardware parts available. If the Alradco kit is tried and true, go for it. You will definitely need relays though.
The HID ballasts have a big surge for startup (23 amps for a few milliseconds) then drop down to 35 watts - about 3 amps per lamp. It's the surge that fails you if you don't use relays tied to the battery.