Old plasma needs streaming video solution

I'm trying to come up with a streaming video box solution for an older setup. I need some AV guru's to chime in to see what is going to work best. The TV is funky, Fujitsu PDS4233W (manual/specs) and a 5.1 stereo setup with a Yamaha RX-V630 (manual/specs). So in a nutshell I've got an older TV with some strange resolution limits and a single composite input, S-video, D-sub, DVI, and component. A receiver that does basically composite, S-video and component, with new media streamers being all HDMI. The way I see it I have two options, go with an older streaming box that supports an older input (probably a Roku) or get an HDMI to component converter. The first solution has the issue of it not being supported for very long or possibly almost right away, plus most of the inputs I've seen are HDMI or composite, so extreme ends of the spectrum. The converter option I really have no idea what the pitfalls are of that. The main services I'm looking to run are Netflix, Amazon, Hulu+ Any suggestions?

Why not just use an HDMI to DVI connector? You'd be screwed on your receiver though... Do any of the streaming boxes you've looked at support hdmi and optical out simultaneously?

I thought about that, the issue is loosing that receiver integration. You essentially have to have the TV set to a certain input and the stereo set to another input. There's going to be some non-tech savy people using this in the mix. it would be nice if I could feed the receiver multiple inputs and output one component to the TV, then people would only have to change the receiver settings.

I've run into similar problems in the past. The most user friendly solution is newer equipment unfortunately.

My GF is tech-inept, so when I had my old setup I programmed macros into a universal remote to assist her with the change between devices.

Amazon FireTV with an HDMI->DVI cable for display and optical out for sound.

I guess my biggest concern is getting a streaming box that will output a signal the TV can't handle. If you look at the supported resolutions and specifications it looks as if this is a 480p TV only. It says in RGB inputs it will accept but scale 800x600, 1024x768 and 1280x1024 all 4:3 ratios too. SO RGB/DVI is maybe not the way to go. Under component it says it will accept everything up through 1080i. So I guess I just have to make sure I can set the streamer to 720p or 1080i and know it will scale it to 480p?