Joe,
The Lutron IR units might work for you although I have to question the ultimate cost and controllability as while they are directly IR controlled, I believe they also have limited different IR codes available, Asside from this, they are not as intelligent as some of the many X-10 type units.
There are a number of vendors of X-10 lighting controls. For basic on/off, X-10 is probably your best (cheapest) source. As far as dimming and "scene" capability, I don't think anyone can compete with the SwitchLinc from SmartLinc. They feature 256 memory positions(scenes), variable sensitivity, variable ramp rates, etc. They hope to ship the new 2 way Switchlinc sometime in January although the original Switchlinc (16 memory scene capability) is still available in limited quantities. I just spoke with them this afternoon and will be ordering some tomorrow to hold us over until the new units ship.
The primary potential problems with X-10 devices are that they send signals over the powerlines and powerlines can often be noisy. This causes a problem in that the dimmers don't get the signals the first time. However, this is where SwitchLincs depart from other X-10 dimmers. They have much greater sensitivity and therefore are much more capable of picking the signal out of the noise.
In addition, there are filters available which will eliminate noise if necessary. The interface between Pronto and X-10 of any sort is carried out by an IR to X-10 receiver which essentially receives the IR event from Pronto and converts it to an X-10 powerline signal, aka PLC for power line carrier.
I hope this helps you in making your decision.
FYI SwitchLincs (current version) are $65 each and rated for 600w load....si8ngle gang device whicg replaces a std dimmer or switch.