OKay guys I throw myself at the mercy of the forum. I have the whole summer, I’m ready to start my first pack. My motto is, if it’s worth doing, it’s worth doing right I don’t want to just slap one together. Now here’s what I need to know. My uncle is a carpenter and is willing to help out with anything that needs to be built like that. What parts should I make myself? Which ones would you recommend buying? Any advice would be much appreciated.
You can’t go wrong with a good carpenter around. With his help, 99% of the pack components can be made at home. The spacer and bumper will be the hardest, but everything else is basically a box or a circle. My suggestion is to download the plans from Venkman71, Norm, and Stefan. After reading over them, it should be pretty obvious what can and can’t be easily scratchbuilt. It’s possible to have a pack that’s very nice without spending a million dollars, since many of the items can be substituted with something similar or can be picked up for relatively cheap if you know where to look. Don’t be afraid to make parts yourself (good Clippard valves can be cobbled together from PVC, for example) and don’t be afraid to add a few personal touches here and there. Above all, don’t rush things and have fun. You’ve got the right attitude!
I second that! I would suggest the same as printing all the plans, read them over and get used to the names of the boxes, what they look like, the placement, etc. etc. Print out a good number of reference photos too. So yeah, make a Ghostbusters Prop reference guide, you can find a cover printout for it in the “Tutorials” page, far left on the home page, towards the middle under “Site.” Some original parts you will definately either have to make or bust some sweat trying to find, depending on whether or not you want your pack to be “screen accurate”, which I am making mine to be, at least sort of. Some of the parts and pieces that were on the original pack are no longer made, such as the pneumatic Legris elbows (little gray elbow looking things with the tubing coming out of them) and the resistors (small dark ribbed pieces with tubing coming out of them). I’ve done some research on my own and was actually lucky enough to find some original parts for myself, but it wasn’t easy, I had to call some places around the US, but I found them 
There is still hope though! There two valves made by a company called Clippard that are still being made, yahoo, and it’s cool because they’re some of the coolest parts on the pack. Anyways, if you can’t or don’t want to go looking for original parts, alternatives are offered through many people on the forum. The main one, and has been for a while, is Propfan Charles Walker. He offers resin-castings of all original parts, including a bumper he made himself, and allll the little tiny things. His e-mail is [email protected], he’s a really friendly guy and will definately help you out! Also a guy named Funkzilla sells just about everything you’d need, from the pack shell itself to MOST little things. Funzilla and Propfan would be a good grouping of guys to get parts from. You’d be set if you got their stuff.
http://www.gbprops.com/forums/viewtopic.php?t=788
There’s a link to funzilla’s parts, they’re going fast, so get over there! Other than this if you have any other questions, this site will definately help you out! Feel free to ask us, but do research first as most everything you need to know about GB props is on this site, or proptopia.com. Enjoy and good luck!
-Thiago