Rich,
Anytime. Happy to help. You do not typically need any kind of amplification other than what comes built into the extenders.
The ones I frequently use are up to 70m (sometimes called HDBaseT Lite) or 100m, so 100 ft is no problem.
Here's a good example of a very high-performance set.
Ethereal HDM-CAT6SC
It claims 4K x 2K and Deep Color support, as well as 3D, but doesn't do Ethernet over HDMI, which I frankly try to avoid anyway. Who wants 10/100, when an extra wire will get you Gigabit?
If you need more advanced capability, and maybe only have a single Category cable and can't run more, but still need bi-directional control and Ethernet networking, check out this
Zektor SoloCAT HDE extender system. It also offers PoE, so you only have to power the system from one end. I normally get these when I need to install a matrix switching system like the
Zektor Palladia III 6x4x8 chassis. This chassis, and it's big brothers the 8x8 and 16x16, provide built-in HDBaseT outputs which include PoE, so they provide signal and power to the end points, or receivers, located at each display.
As far as the Roomie thing is concerned, please don't discount a professionally installed system. Like Jim, I am a supporter and user of RTI products. My clients love them, as I am sure Jim's do, and the reason is because the success or failure of these systems, DIY or professionally installed, is almost solely down to the skill of the programmer in integrating the various subsystems together cleanly. Many disparate brands of control system hardware can be made to work very well with the proper programming. I can't tell you how many 6-figure Crestron systems I've run across with a HORRIBLE interface and underlying logic, so spending more money isn't necessarily the key. If you do go with a pro, ask to see a live system or two, and ask to use it without prompting. If you can't, maybe you haven't found the right programmer. I see you are in the SF Bay area. If you'd like to find a reputable person there who could help you, I would be happy to assist in any way I can. I am a LONG way from there, but I know guys all across the country who are very skilled at what they do.
Finally, whichever way you decide to go, good luck with it!