I don't know the Withney song nor the artists you mentioned.
I'm sure you understand that with the equipment you are using you won't get
the sound you're looking for. Look for the best condenser mic you can get your hands on or at the very least try to download the Antares mic modeler from there site. They have a 10 day free trial.
I can't tell you which reverb to use with out mixing the song itself but I can try to give you some guide.
First off you mught try a delay instead of a reverb. It can be cleaner and less intrusive.
Try to use a slapback (single repeat) from 120 to 300ms.
The delay should be in tempo with the song using the1/4, 1/8 or 1/16 note as a reference. I find the 1/8 note to smooth out the vocals.
Divide 60.000/bpm = delay time per beat in msec and you will typically get the 1/4 note.
You can try to use 2 delays. One a short (35-100ms) delay to thicken the voice and then send it to another delay 120-300ms to enlarge the vocals.
If you add more then 1 repeat, it might smooth out the vocals even more but more then 3 just might cause the vocals to clutter the mix even more.
This is called regenerating the delay. Try to mix a delayed signal with some reverb.
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Reverb
To the point - on a ballad like you asked try to use a long reverb time around 2-4 secs. I like to use a Hall or Chamber on ballads becuase they are rich and some what darker. If the tempo is up beat I like to use a plate.
Don't take this as a rule !!!!. I have used a hall on upbeat as well but in general due to the sound of a hall it tends to get coverd on a uptempo song.
Make sure you keep the Decay time under control. It can fill out the space on your ballad but don't let it get to long or you will lose the tightness of your mix.
The "Predelay" parameter can play an important part to the clarity of your vocals. Try with your ballad a 60-125ms predelay. If you want a bigger sound, then increase the predelay.
Try to keep the diffusion somewhat high, for a smoother reverb for your ballad.
Deduct from every thing I wrote, to your more uptempo country rock song.
Most important !!! - Dont over use the reverb. To much and your mix is a mess. Listen to your mix with reverb and with out. If you hear things with out the reverb that seem to disapear when you put the reverb back then you are using to much. If it sounds washy then back it up a bit. Are your text clear?
if not then back up or try to move the predelay a bit.
There is many more things to take ito consideration like Eq-ing the return
Stereo reverb, Panning the reverb, etc... but this can be a good start.
Remember ! nothing I said here is a rule or a must.
