It should be fine to start with the 2.47. Just remember it will not work with the stock Verizon ROM. But don't worry about that since you are gonna flash a GPS enabled ROM. That warning is there so people with the verizon stock ROM don't flash it and try to run the stock ROM. Follow these steps, they worked perfectly for me (on a Verizon device):
1. Run a spl unlocker - either
2.40 or
2.47 will work. If you get stuck in bootloader run the fix from the stuck in titan bootloader sticky.
2. Flash a radio. You can run the Sprint ROM as others suggest but I found it much easier to flash the radio by itself - I flashed the latest
2.42.30 Radio - You can save it to an SD card that is 2g or less. Just format the card to fat32 (Place the SD card in your card reader, Open in my computer. Right click on card/drive and click format and choose fat32). After format place the Radio on the SD card and rename it to TITAIMG.nbh, then put the phone in bootloader. Press power, camera and reset all at the same time. Then follow prompts.
3. Flash a custom ROM. You can use one of the ones posted here or do as I did and build your own with a kitchen.
The first time you flash a GPS enabled ROM you will need to remove the battery for 30 seconds, re-insert the battery and Hard reset.
4. Call Verizon tech support and get a new A Key. Just tell them that you did a hard reset and now when you make a call it says VZW cannot authenticate you phone. They will walk you thru putting the A Key in.