Im sure someone has a list of rebuild items.  I just wanted to alert you that it can add up real quick.  I usually allow about $1000 bucks for an engine rebuild.  It just seems to get close to that for bearings, seals, gaskets, piston, replacement gears, etc. Sometimes less sometimes a bit more depending on what you find inside.

If you arent wanting that kind of investment you may want to just find the problem and fix that.  If your ready and willing to fork that out then go for it, your bike will be happy afterwards.

You just posted photos of your chain tensioner, which is falling apart.  That loose chain makes a lot of noise.  Why don't you tidy up the chain and tensioner, get those components squared away.  Then see if your noise is gone.

That needle bearing you describe is your rod bearing.  That's a really difficult part to replace.  It requires disassembly of the three-piece crank.  It's pressed together.  It takes a very skilled machinist to reassemble and true.  

You can do a quick & dirty check on the rod bearing (and main bearings too) when you have the cam chain out for replacement.  You can see the right main bearing when you remove the cam chain sprocket on the crankshaft.  Inspect it.  When the cam chain is removed, rotate the engine by hand.  If the rod bearing is bad you will hear it clunk as it changes direction at top center and bottom center.  Listen for ugly noises from the other rotating parts as you turn it by hand.  

Tearing apart your crankcase is complicated and expensive.  I would see if I could eliminate the easy stuff first before digging into the crankcase.  Fix your timing chain and verify that your flywheel is properly tightened.  Once you know that stuff is correct, and if the noise is still there, then maybe consider tearing into the crankcase.

You can see from this picture that the right hand main bearing can be visually inspected without tearing the whole engine apart.

It will be a good opportunity to learn.  

I would like to advise you not to buy the bearings at https://www.motorcyclespareparts.eu/en/suzuki-parts/1994-ls650p-savage-motorc ...

Buying them there is much too expensive. The ball bearing 20x47x14 is a widely used ball bearing and costs an average of less than 3 dollars!!!!
https://www.lagerwereld.nl/search?search=&within=20&outside=47&width=14&short...

And if you want to replace the big end bearing you can also buy loose seams that saves you 25 dollars.

The only thing you should pay attention to when buying brand bearings is, that you buy them from official dealers, because there is a lot of imitation.

Start with the cheap and easy likely culprit.
Cam chain tensioner.
Then see how it acts.
Sure, it
Could have a bad bearing
It Could have a loose flywheel
But,
The cam chain tensioner is a known noise maker
And it seems yours is in pretty shabby shape.