I'm all thumbs myself, and I struggled through it.
The only experience I have with Essex frames is a buddies, and it has a pretty good sized imperfection on the dust cover. Nothing a coat of Moly-Resin wouldn't cover, but it makes me wonder about overall intergity, especially if you had one in a more crucial spot.
This is my first 1911, so I'm by no means an expert, but I'd go with a Caspian frame and slide. Mine was perfect, not imprefections at all, and with going on 900 rounds through it it has preformed flawlessly.
The $800.00 does not include tools, luckily I have friends with lots of tools.
You'll need a bench vise, some needle files and a big mil-bastard, a plunger staking tool, some lapping compound, a beavertail fitting jig, sandpaper, I think that's about it. Lots of filing and sanding...