I also had "freezing" and other problems with windows 7 running 3rd part anti-virus and malware programs. Used CC Cleaner and started using the standard Microsoft Security Essentials and have had minimal problems for a year and a half. I'd recommend this path to anyone.
I religiously run quick scans and one a month run a full scan (takes a LONG time).
I have several Toshiba Satellite laptops and have been VERY happy with performance and reliability. I load them up with max RAM to relieve hard drive effort, and haven't had any trouble with whatever video card option I have chosen. You can get a very powerful 8GB main memory equipped Satellite for about $600-700. That price range includes 17" screen models.
As an electrical engineer, the autoformer looks like a solid idea. for RVer's visiting a variety of locations where the voltage supplied under load will vary or fluctuate depending on number of campers at the facility, it makes sense to compensate for low voltage for all those devices that have motors (A/C, refig., etc.) If you drive a rig with lots of appliances, two A/C's, they will definitely improve voltage stability and the performance of your equipment. Lighting, toasters, radios, T.V.'s, etc. will be less affected. I have no experience with autoformers as I drive a small rig and rarely encounter a sub 110 v condition at my outlets. As to brand, look at reviews, but the patent belongs to Hughes, they have a long history. Happy travels.