Well, money being tight, it kind of puts thing in a tough spot.
If you have the cash, pick up some stock "new take off" type factory 20" wheels that someone removed when they first bought their truck.
The Goodyears work decent on the road and in light off road. They can be found all over now, at tire stores, ebay or local craigslist type ads.
They will be old, but if stored right, they should be fine, and all ready to bolt right on, with factory balancing, etc.
My '07 1500 4x4 sport came with 20's and the prices for those tires are coming down. Ive been through a couple sets of Coopers on them that are more off road friendly, and they do great in snow, light mud, sand, etc.
You can then sell off the 22's in your own ad and make back the money spent on your new wheel / tire combo.
I wouldn't spend money on the new rears, unless you absolutely have to, and don't have the cash to "front" the money on the purchase of the upcoming wheel / tire combo.
A local tire shop may be interested in your current set, and have a 20'' set laying around and make you a nice, tidy package deal that is convenient.