So basically all you need is a power supply for a battery charger, which will use something called a "Xantrex charge controller", correct?
Really, the battery charger is all of this stuff taken together. All you're asking about is the power supply part.
All you need for the power supply are rectifier diodes. As I explained above, these are not SCRs. The exact part you need will depend on how much current the power supply will deliver. Diodes are rated both by voltage (maximum forward and reverse voltages) and forward current, so you'll need to let us know how much current you expect this thing to draw. (If you can find it, the data sheet for the charger controller should tell you this.)
Rectifier diodes are really really cheap, so I wouldn't sweat that part of it. Chances are you can use something in the 1N400X family.
Whether or not you need the filter capacitor depends on the charge controller. I'd assume you do need one, since the controller is an electronic circuit which probably wouldn't be too happy with a lot of ripple, so figure on putting at least 1000-2200µF of electrolytic capacitance where you show it. Electrolytics are also cheap, so no big deal there. (Make sure it's rated conseratively; get a 50 volt cap and you won't have to worry about it blowing up.) And yes, the capacitor smooths out the pulsating DC.