Welcome...

Sounds like you have a Sprinter Carib / Corolla All-Trac (AE95)? Is it manual or automatic? People have put 4A-GEs / 4A-GZEs into these cars & wagons with success, despite some people (who don't read / research enough) saying the gearbox can't handle the stresses. If you go with a 20v, you just need to grind away a part of the block where there's a notch in the oil pan. The notch is for the transfer case which sits behind the engine. (Your 4A-FHE already has this notch in the block and oil pan -- keep that oil pan since you have the oil cooler lines and the notch for the transfer case.)
I believe the GZE blocks are all like a 16v block, which means they have to be ground down where there is no notch. This compromises the oil pan seal, so if you can live with an oil leak, then go ahead and use the GZE or 16v block. I'm doing a build using a late model 4A-FE block, so that I can use my All-Trac's oil pan. I'm sure you could use a 20v GE block with a 16v GE head, and not have that oil leak. 20v blocks do have oil squirters as you can see below. Of course you should change out the wiring harness and ECU for GE (or GZE) ones...
Here are some pics of blocks showing the oil pan side, all oriented the same way (oil pump on the right side). Last pic shows a 20v block in the process of being ground down for an All-Trac's transfer case. I posted these in another topic here, but it's worth showing again:
Early 4A-FE block:
16v 4A-GE block:
20v 4A-GE block:
20v 4A-GE block, being prepped for an AE95: