The PRO-97 & PRO-2055 are the same scanner. One is just the base model and the other the handheld model. I use and recommend WIN97 to program them (www.starrsoft.com).
When it comes to cables, there are two versions: USB or COM. If your computer has a COM port (9 pin connector), then the COM version cable works great and is a lot cheaper. They are no longer sold new, but you can find them here and places like eBay easily. The cost should be around $10. I have bought some for a lot less than that.
If you have only a USB port and/or want to get the USB version cable, that is the 20-047 cable from RS people speak of. It is $34.97.