8v even this head isn't considered best flowing ever, or any other guys 8v ported head. For the money you can't touch the Neon head, 300+ CFM on the intake for $400 in CNC porting from Indy. Then with a Ported Indy intake or another built 16v intake like LW / Lonewolfs to feed it. FWDperformance has sold LW parts over time too, never know what they may have in stock.
Keep in mind if you build any of the 2.2 / 2.5 16v engine it is going to be a lot of money. The T3 needs a lot of money in it and gone through if you buy that engine outright and you need all the wiring. Then the Masi, massive money everywhere. Then the hybrid, custom machine work and pulleys etc. So the 8v isn't that bad of an idea.
Then there is an engine swap. This is the most power per $, adding the PT / SRT 4 2.4 turbo engine into the older car. Hone it and add rods and pistons and a few little HD mods and your ready for big power. You don't "need" head work, intake work, or tons of custom little mods.
So going that route isn't a bad choice for the max power.
Now for the questions.
655, 81-82 Chrysler head. This head uses the full intake gasket port window and requires a custom intake to use it. Even if you don't go ported. This head is basically the same as the G head, even with parts. The difference is the ports, they are a lot bigger. The 782 is more different than any of the other heads.
Lonewolf / LW intake for 8v, pictures I've seen show the intake cut to a 655 port window and they opened the 782 to the port window. So maybe a little bit of porting and it'll work with a 655, or no work at all if they set it up for it.
Many of us old TD folks would rather play with the 8v, I don't think there is a logical reason for many just choice. The other reason for me is I have 2 numbered cars I don't want 16v engine swapped.
For you, your not in the US. Going out and doing a complicated engine swap over there is going to be up hill. I also don't know about the legal issues over there with it. For you buying a ported 8v top end and bolting it all together. Then using a stage 5 computer to tune it is going to be your best choice. But that is because of where you live and in the long run you may not need more. Shadow is already moving to the end of the HE351 with an 8v and with a stage 5 computer. So if you can max the turbo you have basically with 8v there is no serious need for 16v.
I would talk to FWD about filling in the blanks. I would at least have a fully ported 2 piece with plenum on any 8v head with that turbo. Those aren't cheap. So at that cost level the LW intake doesn't look so bad starting from scratch. I port and I own 2 piece intakes and I can make my own plenum, little cheaper that way lol. You you pay for it out right the LW intake combined isn't so ugly in cost. The 655 with big valves should be a little cheaper than the other heads, but only in labor as the head is faster to port. It isn't the MASSIVE work the 782 is.
I like my valve train the best lol, no supprise there. The Beehive thread and the PT thread. Cam has to do with which head, buying something out right the FWDperformance F4 with the D window heads and the TU R2+ for the 655. If you can buy custom a .550" lift version of the F4, same duration, centerline, LSA, etc would be best on the 655. There isn't really a cam made for it anymore. Depending on the flow curve it may need the .610" lift like Crane sold for it with turbo cut lobes, that would also mean longer valves (.1" longer installed) with either off set locks or a .050" spring shim. Then comes the lifter, I know the PT is fine with .551" and 7,000+. But .600"+ lift? People may need mechanical lifters and another .015" lobe for lash.
So like any engine you add a cam made for how the parts work together. In this case the 655 is going to work differently than the other heads because of port volume. The best cam for a ported 782 may not be the best cam for a 655, that is just the reality of it. With a 440 you can't run MP cams with Indy heads like you do with 906 heads, not too different really.