It looks like your TV's native resolution is 720p. Although it will accept a 1080i signal, the max it can actually display is 720p, so there is really no benefit to getting a higher resolution player since the content will get downconverted anyway. Plus being a rear projection, the image is going to be softer than a current LCD or plasma.
I've owned all of those players. I preferred the sony overall because it had many more streaming apps. I sold mine on ebay quite a while back for under $100, so I would expect them both to be pretty cheap by now. As I recall the amazon app on the panasonic would never stream HD for me, and it didn't have a Hulu app. It's Netflix app wasn't bad, and it's DVD upconversion was better than Sony (but you won't benefit from that at 720p). Sony's Netflix app was terrible in my opinion, but the picture quality was good. I didn't keep the samsung very long, so I can't really comment on that one.
All that being said, I would stick with the 35 for now and just get an old Roku XD. Then when you eventually have to replace your TV, get a better blu-ray player at that time. That way you haven't wasted money on an inferior obsolete player.