Crowns are great amplifiers. The CDI1000 in particular is a good amplifier and has lots of flexibility. Not to mention they are built very well Built in DSP, with a good amount of processing power. The CDi doesn't have RCA inputs however. They are balanced input and pro stuff has a lower input sensitivity so you will also need a signal line amplifier to bump that signal level up
The I am not familiar with the XTi, but I think it is like The CDi lines little brother. I think a CDi1000 is a bit overkill for your application I think. You probably wont need much if any of that processing and it's a lot of power for a single Type R.
I'd go with a plate amp like the previous poster mentioned. It will be a cheaper, and you will have RCA inputs therefore not needing a line amp.
If you are dead set on using a pro amp, Go with a QSC ISA series amp. I have a ISA280 powering a 15" Type R right now and I'm running it at 8 ohms bridged and getting decent-good output out of it (needs a new box). It is a little more straight forward amplifier that's cheaper and will probably do exactly what you want.