Without any specifics such as intended use, range, backyard size, etc. Any comments would just be personal preferences. Elaborate more and you will get more comments.
I went with .22 just because the ammo is much more plentiful and usually a little cheaper. I mainly shoot targets and rats, so .22 is plenty for me. The beauty of the Dreamline is the versatility, you can always purchase a barrel kit in .25 later on and then essentially have both at you disposal!
I'm not aware of any dealers in NJ, I purchased from Trenier Outdoors, who is in WI. Jeff is great and will take good care of you. He may also be the closest FX Vendor to NJ. FX doesn't have a dealer locator on their website that I could find. You could contact FX USA at [email protected] and ask if there is one closer.