To me, a lot of your choice is going to revolve around how you want to move and store the panels. A 100W panel is 26" x 44". For me, moving anything bigger would be tiresome. If you can make some type of exterior mount that doubles as the transport holder like some have done on here, then panel size isn't such an issue.
If you're close to SolarBlvd, they seem to have good prices and sell pretty good modules. I'm a happy customer. The kit with free shipping and the included controllers with wire is a good value. I'd probably choose a better, name brand controller and pay the extra for wire, if I was doing the small system.
FWIW, I went with a single 235W panel and MPPT controller, mostly to be able to have easy future expansion that fit my roof real estate.
