Well, you've got me with the Daytona but I'll pass on most of the rest.
This belongs in the MKIII section (1986.5 - 1992 (1993 in Japan) is the MKIII).
Unless it's been swapped (a good thing to find out) it will be a 7M series. This is the only series which came to North America and was the ONLY engine in the MKIII Supra until '89. Turbo models are the 7M-GTE and N/A are the 7M-GE. These are cast iron blocks with aluminum heads. They came with a composite HG from the factory which they are
notorious for blowing... This is due to too low of a torque specification (Spec is only around 56ft lbs, should be around 75ft lbs for bolts and around 95ft lbs for studs). The fasteners are not TTY and may be reused if they pass a close inspection; I don't reuse 20yo fasteners but they should be fine if they're not pitted and haven't been torqued beyond their capacity.
The head should definitely be milled. If the block deck is flat and true and free of pitting or warpage you may use an OEM composite HG with little concern for it failing. For higher performance builds a MLS is a common choice, but for this you really have to get the block deck cut too; From the factory they just weren't smooth enough.
Detonation damage isn't terribly common... at least not in systems which are largely stock. But yeah, if you've got to take the head off, well, you're already there.
Other than the HG problem there's not much else that doesn't come with any 20+yo performance car which people like to buy just to beat the snot out of...
Good luck to ya!