I picked up the Sammy 850 only 1 month ago and I'm sure they have more in stock from Mt Ommaney Retravision if you are in Brisbane. Best price I got was $190. Comes with HDMI cable so is a bargain since you don't have to fork out extra $60 for the cable. Extremely happy with the build finish and picture quality.
I also have spent time looking at wall mount arms. I think you answered your own question when you said you wouldn't trust some brands with your TV. You get what you pay for. Have put off buying a Vogels arm mount at this stage as just happy with TV on unit. Have a look at the "skunkworks" website, aussie made brackets, certainly stong enough, big range and cheap, BUT bloody ugly compared to Vogels. Vogels have much superior finish and look fantastic. I know its behind a TV but if you get the arm mounts it will be seen if pulled out from the wall, however with flush mounts it doesn't really matter. Good Luck