Before you buy anything - measure it. Borrow or buy a set of Vernier calipers, and measure all the bores, bearing journals, etc. Use a good flat edge to test the block and head faces. Metal rulers work well.
What work you do will depend on the measurements you get.
Invest in a Gregory's or Ellery's manual. Personally I prefer Gregory's, but that's me
It will provide you with all the tolerances, torque settings, etc. Also a detailed how-to on setting up the valve timing and a complete strip-down and rebuild of the entire car, including motor and gearbox. Cost about $30-$40, well worth it.
Rebuild kits - will vary depending on what needs doing.
It's probably a safe bet to assume the engine needs boring. That means $50-odd per cylinder, plus your piston/ring set.
You will need a FULL gasket set (rocker cover to sump, including stem seals) and head bolts. Veale are usually good.
You will need new main bearings. If the crank needs to be ground, you need to pay for that as well. Usually in the region of $100 for crank grinding. Obviously if the crank is ground down, you'll need oversize bearings, so don't buy them until you've measured.
You can balance it as well if you like, probably not necessary for your application. Costs about the same as grinding.
Does the block need decking? If so, $50.
That's the bottom end.
New timing chain/guides. Umm I *think* that's worth like $60 but I don't remember.
Lifter rebuild kit? About $12 from Repco, there's a thread on here somewhere with the part number on. That does all 12 lifters BTW.
Any head and cam work you do.
Intake/exhaust gaskets *should* come with the gasket set. Check.
About $20 for some valve grinding paste. It never hurts to stick some of this on the sealing surface of the valve and use the drill (slowly!!) on the valve stem to clean up the valve seat a bit.
Does the head need facing? $50.
You won't need to replace the rockers and pedestals, no.
Umm I think I remembered everything