might as well go the best you can afford while the engine is out and already opened up.
forged pistons and stuff arent that much more expensive compared to OEM stuff.
gorilla industries have a real good deal on engine rebuild kits have a look in there
cheers 

If you had spun a bearing you'll see metal shavings when you drop the oil now. Additionally, may help or not but good to know. HKS cams are somewhat "soft". Mine have a few flatspots (been running them for near 10yrs) which makes my cylinder head kinda "noisy". Valve clearances etc are all perfect too.
 
Either way, a decent mechanic (probably not the one you just went to) could identify/diagnose the issue. Does sound like a bearing though.

I decided to get a engine n rebuild my old one as a project,
With a bigger head ache the car is still not running thanks to two work shops that not only f****d me nicely but left a nice big hole in my wallet too,
So now,
After everything and car catching on fire it still continued to mis,
haveing to work on it my self I had a vac leak from plenum decided to replace it n get rid of tvis replacing it with a plate (not sure if it was a good idea)
started car drove like **** kept missing and I just can't figure out why,
put it together again and now my alternator ****s it self
Better yet I got EPA for exhaust noise, aswell
So now I'm sick of takeing short cuts
I have to do it once or it's gonna be up for sale,
I removed my piggy back so running standard computer, in my wireing loom I've got a lot of different plugs not connected and I can't find where they go.
My biggest questions are,
Is there any diagrams for complete wireing plugs for the engine bay? What plug goes where so I can get rid of the rest,
Would the standard ecu be affected by Removeing tvis,
A diagram of vaccum hoses?
What are the biggest problems with the gen 2 motor ecu,
And is there any prossibilities of why it's still missing and still haveing a vaccum leak,

I have never come across a car with so many problems and so many dumb mechanics

I just wanna sit in the car and drive it and go to a mr2 meet lollll

If anyone can help me ill buy u u a slab dead set,