When you say "IR dimmer unit" are you talking about a x10 switch or plug in module?. If so your options as you have found are pretty limited. You can set up several dim or brighten commands up in a macro but it still falls far short of achiving what you have in mind. Also as you have noticed you must come to full bright before you can dim. What you need are indead scene capable switches. With them you can set ramp rates from instant on to 13 minutes. You can set them to come to preset levels and also they return to the previous level when turned back on. If you have more than one switch each can be programmed individually (ramp rate and levels) and then all operated will one X10 command. Take a look at PCS smartswitchs at
http://www.pcslighting.com for more information. I buy mine at
http://www.homeautomationnet.com and have been very pleased with them. For a HT setup they really do the trick.