Lanse I have been messing with chevrolet engines and vehicles for two decades, both carb and fuel injected. I've done this when I was poor and broke and when I had money to spend. Here's what I say:
Go with the carb. The TBI is not a bad setup, but:
1.You will have wires running all over the place.
2. The setup you have is already 20 years old. Sensors and wiring connections can deteriorate and develop intermittent problems. These systems tend to get cranky when they're older, just like an older desktop computer.
3. If you go aftermarket computer you will spend way more than a good used carb and manifold.
4. Small block manifolds are everywhere and insanely cheap.
5. Carbs are everywhere and cheap unless you insist on a brand new one.
In '87 Chevrolet changed the angle on the four most center bolts of the manifold to go straight up and down. That's two on each side of where the carb goes. The other 8 at the corners are the same. The advantage of an aftermarket intake is that you can get one without the EGR valve and a dual bolt pattern for the carb. (will work with Q-jet or Holley).
You want a pre-'81 HEI distributor with the 4 pin module. Billions of them out there. Only needs a single 10 gauge wire to run.
Now for some clarification. By 93, Chevrolet was using the "Vortec" name on their engines and in their advertising. The better performing "Vortec" heads that you may have heard about did not come out until '95! You can spot those because it will have only 8 bolts on the intake manifold and they all go straight up and down (relative to the ground).
You said it needs a head gasket, when you get it apart look for cracks and any sunken valves. The good news is that any small block heads will bolt on! However, you want to try to stay with 305 heads or Vortecs or you will lose significant compression.