I'm with Capt Mick, preferring to rewire myself. I'm an electrical idiot but I learned a lot rewiring from scratch, and I am more comfortable knowing that I used quality materials, made quality connections and know where everything goes and what it does. Truth is once I figured things out, it was very relaxing to crimp terminals, melt adhesive heat shrink, and screw in terminals to switches, panels and gauges and grin to myself when they worked. Kept looking for more electrical stuff to add.
Anyway, I reviewed the site, products, and prices before spouting off and in summary, I think you will find better quality for less elsewhere. Their how to section could be useful regardless of the path you choose.
Consider having a look at
www.genuinedealz.com for basic electrical wiring needs. They'll even make the connections for a buck per end...
If you haven't done much dc electrical work, consider buying or checking out Nigel Calder's book "Boatowners Mechanical and Electrical Manual." Or Ed Sherman's "Power Boaters Guide to Electrical Systems." I found both at my public library and they are available through any good book store or Amazon.com for about $30 each.
Finally,
www.bluesea.com was priceless for me in providing a lot of ideas and technical understanding of what things to incorporate into my electrical system. Their tech advisers are excellent to work with on the phone, and I say that because I repeatedly called them with "stupid" questions which they graciously answered to my satisfaction.
Take your time, document or draw up what is there - especially if it works, and then use that as a guide for what you do, again drawing up what you do. The result will make you a safer, more confident boater. And you'll have saved a lot of money...Good luck with the project.