I asked this question just over a year ago and now I have a registered working goblin.
The forum told me basically what they are telling you... you can probably do it, but it won't necessarily be easy.
My son and I took this on and we managed to make it through, but there are definitely times we just wanted to throw in the towel. The wire harness was a beast, but in the end everything electrical works and works well. It just took time, a number of questions to the forum, some rework, etc, etc.
I did end up buying a lot of tools. I totally agree with the torque drill (I got a dewalt). That is my favorite tool that we bought. I probably went overboard, but I had to get a bunch of larger wrench sizes, torque wrenches, soldering iron, riveter, caulk gun, jack stands, dolly, etc, etc. Now I have all those tools to use, which is cool, but it was a bit up front.
We didn't end up buying an engine lift. We just put a wood pallet on some tire dollys, jacked up the car, wheeled it under and then lower the car onto it. Undid the bolts and jacked up the car and wheeled the engine out. Then reversed the process to put it on the goblin. Worked very slick.
Anyway, if you are committed and patient, you can do it. But you have to really want to. Like I said, several times we nearly packed it in, but we really wanted to build this car, so we just kept coming back to it and got it done. It took us almost exactly a year and whole lot of work. I think it was worth it.
I would tackle each challenge as it comes and don't look ahead too much. That can get really overwhelming. And be prepared for the simplest of things being difficult and taking longer than you expect.
We also have some really cool memories (which was the main reason we did this together) like:
"Remember that time we went and got the donor car and that tractor pulled it out of the muddy field and put it on the trailer and we wondered what we were doing?"
"Remember when about broke our hands using that stupid hand riveter to put the bottom on the car?"
"Remember when we cut the donor frame up into 5 sections? In the morning we had a car and in the afternoon we had a bunch of scrap metal and then we hauled it to the junkyard and got $30 bucks?"
"Remember when we didn't have a living room for 3 weeks because it was too cold to work in the garage and the wire harness needed to finally get finished so we brought the whole thing into the house? Remember how grandpa came and got a chair and just sat there staring at the harness mess for 15 minutes shaking his head and asked how we were doing all that?"
"Remember when we got the rims from the junkyard and took them and got them powder coated and new tires put on and how they now look really cool?"
"Remember when I wanted that extra screw to keep the side more secure and forgot that the coolant hose ran through the bottom frame tube? Remember how that little green water fall came shooting out the side and I started screaming like a little girl?"
"Remember the first time we got the engine started and jumped around and yelled like we had just won a championship?"
"Remember when we got the tires and brakes on and we took that first little test drive and couldn't stop smiling?"
I could do this forever. Lots of pain along the way and lots of joy with a lot of good memories.
If you're up for that, go for it.