It really just depends on which modules you want and if you want to be able to add extra sensors. The actual LoRa module is the same on all of them (make sure you order the correct frequency for the location you are in though). The RAK19007 is the baseboard in that picture, the RAK19003 is a smaller board but doesn’t have as much space to add extra sensors etc. If you want a screen then make sure you order one with the OLED display. 

 Thanks man. I’m looking at this one (with screen) although I also saw you had listed one without the screen, then purchased a separate screen. 

If I start with a prebuilt one from LilyGo, and then build a second one from parts via rakwireless, would you advise getting the kit with screen attached, or the lower one in this photo and then attach the screen myself? Does it matter? Or is it choose-your-own-adventure? Lol