It was really easy. I would say the most difficult part is determining which side rail is the positive and which is the negative.
Here's a list of everything I purchased:
1x 100w cool white array -
http://www.ebay.com/itm/300639533243?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
1x 100w warm white array -
http://www.ebay.com/itm/330660077325?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
2x 100w constant current drivers -
http://www.ebay.com/itm/330660091340?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
2x 5.88" x 6" heat syncs - If I were to do it again I would go with slightly larger. And keep in mind that heatsyncs vary tremendously, for instance these are ~3x the weight of other similar sized syncs -
http://www.heatsinkusa.com/5-886/
1x Artic Silver 5 99% silver thermal compound -
http://www.radioshack.com/product/index.jsp?productId=2216879
4" fan
2x $0.89 extension cords
Tools I used and other small stuff I had on hand:
Solder gun and solder
Screw driver and screws
Drill and drill bits
Electrical heat shrink, electrical tape, or wire nuts.
I'm pretty sure that covers everything. I added a reflector I had laying around and cut up some 24oz aluminum cans for reflectors but I wouldn't say that's necessary