super gun build, controller, solding, and more

[runawayabc123]

Hi every body, first post!

First I have a hand me down soldering iron:
http://www.xytronic.com/pi/168.htm

What do you recommend for tips?
http://www.xytronic.com/pi/168-tips.htm

I have a long 2" rod type one (not pictured).  It is a little blacken and bent (not bad).  Do I need to replace it?  Mostly just wire solding for now.  For now

I am building a super gun/jamma harness to my TV.  I ordered a bunch of buttons and joysticks (my first game is Teenage Mutant Ninja Turtles).  I am going to be designing my own smaller/portable controllers (over say a table).  I have some card board try out models that I will complete this weekend.  My main question here, is are all grounds equal?  I have a few wiring manuals and some specify more than others for grounding.  Grounding.  Feel free to school me on this one.  I know it needs to be a good ground.  I plan to make my controllers out of 1/2" wood when I get a good layout. 

I am also going down the light gun route.  I have a few orders for a couple light gun games shipping as we speak.    Any recommendations on getting these to work best?  Maybe I will make my own light gun cable adapters. 

Also, I think I want to make a jamma board "pin saver" (aka extender) to keep the pins from being overly chewed up as I switch games to play.  With the 3/4 players and light gun games, I don't think a 6 changer setup will work well.  Unless I make my own.  (Open to thoughts on this one, that could be a lot of fun.) 

List of things I bought:
Speakers
Arcade Power Supply
Jamma Harness
4 Joysticks (4/8ways switchable)
Tons of buttons (arcade style)
RGB to NTSC converter
2 Konami 3/4 player harness (yeah, I could have made them, but oh well). 
Tons of female quick disconnects

I think this new hobby is going to be a lot of fun. 

[runawayabc123]

I forgot to add, I come from a family of Do It Yourselfers who over build things and my dad talked me into buying 18awg wire for the controls and stuff.  This won't get me into trouble, will it?  Thanks.  (Other than being over kill and more expensive of course.) 

[jennifer]

        For what you say, the 401, 402, or 403 would be my choices. The other styles are more for board work. Get a few though as they burn and pit
needing to be replaced.
        If you need a say -12 ground, this could be achieved from a switcher power supply, this is usually a transisor circut thing however,
unless your plans call for something different , a good neg. ground will suffice. That is to say, the  +/- from the power supply.
        The the wire connected to say the case of the power supply is also called a ground, or earth, [usually a green wire]  This is a path disperse
stray/problem voltage to the earth.
         Anyway..... BLAH, BLA, BLA..... Glad you finally made it here!      

[lilshawn]

i'd say 404 (which is about the same as the tip on the Hakko iron I use.)

it has a little broader tip for larger solder areas, but can be turned 90 degrees to be used as a point for precise work. it works pretty good for most stuff.

[runawayabc123]

Ok, so my tip is toast.    I will be ordering a few more, however that site also sells diodes and transistors. 

If I want to build my own switcher for jamma harnesses, how do I know which size diodes/tranistors to get?  I will need transistors for the power supply wires and grounds, diodes for wires feeding power out (like video, controls, speakers, etc). 

Thanks.