DIY is sure possible if you've got the skills. The G43 is just a ceramic rod in a glass slide with a variable power supply. But you will need some electrical know how or be a good study. Plenty of stuff on FC.
For the elev8r. You would have to remove the coil and glass balls to use with a torch, too much hassle especially since the coil needs to be as firm as possible for best heat transfer. If you buy it already set up from vgoodies or 7th floor you don't want to take it apart. But the heaters can be bought separately inexpensively.
You can't use the FP coil on the elev8r if that is what you were asking. FP is 20mm elev8r is 16mm.
If you are going to get a FP then maybe just the torch kit is for you. Hitting the E43 side by side with the FP it is very hard to tell the difference. But torch is a nice option and inexpensive enough to have as well. Also good for when the power goes out, or after the zombie apololypse.