I built an early version of the HF Packer for a friend. It was a good thing because he didn't have any constructions skills. I didn't have any issues building it and when it was done it worked great. I expect the new ones work just as good, if not better.
However, I would expect the Hard Rock does have output filtering, even if they don't mention it. I don't see how it would be usable without the output filters.
Another option would be to find an old CB amp and modify it. I bought a 150 watt, 80-10 Meter "Broadband" Amplifier at a Ham Fest for $15. Of course, it was a CB amp and had improper bias (none) and no output filters. But the basic amp design was solid. Add some actual bias with a old 723 and a output filter from the ARRL Handbook and your all set. All of the old CB amps were made to run full power from 5 watts input. It has RF sensing for the RX/TX switching, but you might have to work something out if you need to run full QSK.
73, Martin, K7MEM
Ash Fork, AZ
In my area, it seems that every pickup truck or SUV comes with one or more dogs. It's so common that I can only assume that the dog(s) must come with the vehicle. So logic tells me that, if you want to keep the truck for a long time, go for the multi-dog option. Otherwise, if the dog dies, you have to buy a new truck. I have five dogs (4 dogs as of 4/4/2013, RIP Katie), so I'm set for a few years.