Just wanted to share my experience with this Harken hoist system.
Here's the link http://www.amazon.com/gp/product/B000AQNRQI/ref=oh_details_o04_s00_i00?ie=UTF8&psc=1
I paid about $100 for it, but I searched around for this price.
Overall, it was very easy to install if you are comfortable drilling holes in the ceiling/trusses of your garage. My only suggestion is to take your time laying it out as the mounting location of the block and tackle is critical to ensure the ropes lower and raise to the correct height. However, almost everything is adjustable, so mistakes are easy to correct.
I use this system to store an Adventure in the garage. With 9 ft ceilings, I have plenty of clearance to walk under it (I'm 6'2") and park my SUV. The 145 capacity easily handles the kayak and about 15-20 lbs of gear I leave in it. The supplied straps will scratch the plastic hull, but it is minimal. If you are concerned with small scratches, I recommend covering the straps with foam tubing (e.g., tubular pipe insulation http://www.homedepot.com/webapp/catalog/servlet/Search?storeId=10051&langId=-1&catalogId=10053&keyword=foam+tubing&Ns=None&Ntpr=1&Ntpc=1&selectedCatgry=Search+All
The best part of the system is the ability to lower and raise the kayak to any height you like. I even lower mine to about waist height for easy access to work on the kayak or load gear. Then I put the scupper cart in with the retaining pin, lower it to the ground, and roll it right out of my garage down to the dock.