(E39) 520 to 530 Halfcut. Interior/Exterior help. Side story for entertainment.

Hi everyone, need help. Please advise sifus and gurus.

If you don't want to read this part then go immediately to questions area.
Ok here goes. Well early in the year I was desperate for a car coz I don't believe in Malaysia new car prices. Brought my dad along to check it out, an E39 520i, he tested it and said it was ok. But we didn't check deeper. I got the car thinking it was ok. The interior was so so. Thinking that I would be able to replace some parts. So, brought it back for a few days then when I looked closer at the odometer which listed 100k++, I actually realized that the 2nd hand dealer put black tape on the SIDE of the '1' of 100k. It actually was 300k+= km! (Since E39 odo is digital therefore a digital '3,7,8,9' number, if you cover the side can be made into a '1'. If you get what I mean). They even put black tape to cover the 'airbag' light. Gosh I was crushed. Went back to bang table and got some compensation but that's that.

That's where the problem started too unfortunately.
-Steering rack bad leak. Replaced.
-Spongey suspension. Replaced with some suspension lying somewhere.
-Replaced reservoir tank
-Engine mounting
-Upper arm
-Intake rubber boot
-Etc, etc etc.

About a week after repair the car would kick/jerk when trying to change gear. Then the yellow gear light would come on and I would be stuck in 4th gear all the way. Threw my car back to the repair guy's face and found out they didn't fill in enough oil to the gearbox. :62: They said they will fix.
Then one day was driving and accelerate on the highway then suddenly tons of white smoke behind me and the smoke was getting into the car. Yellow gear light comes on again. I'm stuck in I believe 5th gear now. Hardly can move. When rev to 5-6k rpm only move like 3km/h.
They tell me have to change gearbox coz of burnt clutch. A mechanic coworker confirmed in his electronic console thingy that there were two major faults

So basically for me my situation was 'sudah jatuh, ditimpa tangga, lampu dinding, kipas, cabinet, dan photo frame'.

You've read till this far eh. Ok, just a little bit more. So now I finally brought the car to my workplace workshop at OverDrive, Kota Damansara. A coworker is familiar with BMW and will do a halfcut for me.
My goal:
Halfcut M54B30!!!
Do interior
Do exterior

My questions for you:
1) Any references for good/honest places to get halfcut and approximate price? M54B30, [No need them fancy m sport stuff. I want to custom body kit later]. I remember reading a post from Herbert that 'Chan Used auto parts' may have them. But that was 2011 post. (+1 for research). Still got there or any other places?
2) Is my decision for a halfcut wise? I'm thinking that my car has not much resale value anymore at this condition. So maybe I could spend a bit and I can make it great. Your thoughts? Or you have better solution I'm willing hear.
3) Interior. I need references to a place that can do interior customization/restoration at a decent price. I would like to make it look good again. Something you can bring a girl dating with. (I researched also that Herbert mentioned about carzonepro). Or should I just go to the halfcut shops and take whatever interior stuff I need?
4) At the bottom of my car to my utter surpise it was rusty like hell. Some places got dents. Missing tyre-wall panels. Broken bottom panels which was tied with some wire fencing wire. Who can repair this? Please Please Please let me know. Also need to do a few dent fixing in the engine compartment area. Magat.

I know that I made a mistake. But I still truly believe that E39's are beautiful things. Now I need your help. Thanks for reading so far and hope to hear back.