Common sense usually involves grammar........
you can pick up whats known as a VRS kit (valve Regrind kit) off ebay for pretty cheap im in Australia and it set me back $90aud to my door ($40 for the gaskets and $50 postage!)
The VRS kits usually contain, Intake manifolds, Valve stem seals, Head Gasket, Cam seals even rocker cover gaskets and a assortment of other gaskets you may need, even if you don't use them all its handy to have.
if i were you id pull the head off and do the head gasket as well, i had a friend drop a valve while doing this, i laughed at him, he laughed at me when they managed to fish it out with fishing wire (true story, not on a supra tho)
The 7M valves are difficult to say the least to fit springs. I've done a set of v8 (12v) springs on the car using a allen key through the spark plug hole to hold the valve in place. my spring compressor dosn't seem to fit NFI how you compress the springs i sent it to my engine shop and said here fix it...
Collets/retainer plate - you don't need new ones unless you run into spring bind and need extra clearance, these don't wear easily.
Springs - Try ebay $100usd for a set of 24
Shims - Toyota a few $$ each
Gaskets - $40 ebay