The Little Yellow Truck

I've had my grandpa's little yellow truck for a few years now. Doing small upgrades here and there, but I'm looking for something bigger. I feel like I'm ready to start a major overhaul on the entire truck; however, I don't know what exactly I want yet. Maybe a little help on this?

So far this is what I have in mind:

Custom frame, built from scratch idk?
New interior, starting from scratch or customizing what i have idk?
HID head lights for sure
Synchronizing headlights and brights probably
Train horn lol idk?
Super smooth suspension (no bags through) ideas? stock height
LED tail lights?
Motor/trans/diff swap? no clue what to put in there?

Any ideas on all of this?

I've been checking out the forum and I love what burnzya has done. This is a really clean frame for his 73 hilux. I'm thinking I might start here. What size metal should I use lol?

I am trying to tackle some wiring issues. First and foremost, I want to tackle my fusible link issue. The fusible link to the headlights was melted so I figured instead of rewiring fusible link every time I have a problem, why not install an inline fuse holder and just replace the normal fuses that we all know and love. Anyways, I have three main questions about doing this.

#1 What amperage does my fusible link melt at?

#2 What fuse size (how many amps) should I run to each of the two links that are being replaced? Should they be different? (I think so)

This is what I have gathered:

There are two fusible links, one goes to a white 12 gauge wire and the other goes to a red 14 gauge wire. The 12 gauge wire powers the whole truck minus the headlights. And you guessed it, the 14 gauge wire powers the headlights.

The alternator by definition in my manual puts out about 40 amps.

The fusible link is about a 14 gauge. I read on another site that since it is a metric based vehicle that the link could be 3mm fusible link. Not too sure about that.

No fuse in my truck is greater than 20 amps. I have four 20 amp fuses and three 15 amp fuses that are all connected to the 12 gauge white wire.

#3 Do I only need to send 20 amps down the white 12 gauge wire since no fuse on that line is greater that 20 amps? Or do I need to send more that 20 amps since it is supplying four 20 amp fuses and three 15 amp fuses? (I'm thinking the latter)

My headlights are supposed to operate with 37.5/50 watts (depending on high or low). I have no clue how many amps I should be sending through to the headlights.