I have 1997 mitsubishi Eclipse GS, 5 speed with a 420A, what parts would I need to drop a factory turbo in it besides the: turbo, manifold, intercooler, injectors, fuel pump, blow off valve, and bigger pistions and rings? 

Humberto,
Personally, this is not a job I would do, or recommend be done. With the time and money required to go into it, you might as well buy an entire turbo engine and drop it in. At least that way you know you have all the parts and you can sell your N/T engine to help with the cost. But that's just my opinion.

You don't need to replace your pistons. In fact, 2G non-turbo pistons provide for just as good compression as turbo pistons. Though, you should replace your rods with either aftermarket rods, or 1G rods.

Here's a general list of the items you would need. Check off the ones you already have or know about:

1. exhaust manifold
2. 14b turbo
3. 02 sensor housing (mine was ported)
4. the turbo 02 sensor (it has a longer wire, to reach around the turbo, you don't need it if your wire already will reach, or if you rewire it yourself)
5. turbo fpr to match the 450cc injectors
6. 450cc turbo fuel injectors
7. resistor pack for 450cc injectors
8. m/t federal turbo ecu for the year range of your car
9. wastegate actuator
10. aftermarket boost gauge
11. new fuel injector o-rings
12. new exhaust gaskets
..
..
15. 90 degree bend 2" id coolant hose
16. vaccume check valve for the purge canister line
17. UIC hard pipe and bov
18. soft IC pipe from IC to UIC hardpipe
19. stock turbo intake accordion tube w/ bov hose
20. turbo MAF and pigtail for wiring harness
21. spool of 16ga wire (a bright color, so it's easier to see in dark spots)
22. wire loom, solder, electrical tape
23. fuel pressure solenoid and pigtail
24. knock sensor
25. stock sidemount intercooler
26. lower i/c pipe and hose w/ gasket
27. turbo aircan (optional)
28. turbo downpipe
29. turbo car oil pan
30. oil drainback tube
31. 5 feet of 3/8" coolant hose
32. turbo oil feed line w/ banjo bolts
33. turbo coolant lines(or make some with 1/4" steel pipe fittings)
34. a tube of high temp silicone sealer
35. 3 extra (harness side) ecu pins
36. bolts for the turbo-to-exhaust manifold connection and that one nut (you can use normal hardware store stuff, but you might want to get the correct bolts from the dealer)
37. copper gaskets for the lines
38. a whole pile of various vaccume tube, connectors, hose clamps, and an assortment of bolts and nuts(you can never have too much of this stuff, just incase)
39. a parts runner car
40. change your coolant and put in some Redline Water Wetter too
41. oil filter
42. 6 quarts of mobil 1 (keep a spare one in case of leaks)
43. A 5 gallon gas can full of 93 octane gas, and a place to get rid of the 87 that's in your tank right now.
44. reset your plug gap to the setting for turbo engines
45. set the ignition timing back to stock
46. EGT gauge (get a westach or greddy, automoter and vdo don't work as fast).
47. Act 2600 clutch w/ street disc

Sound easy? It's not. All my friends that have asked me about this conversion, I showed them this list of items, and they usually cool off on the idea. But do this at your own risk.
Good luck!