Tippmann 98 custom, only 100-150 bucks. What makes it the best is the flatline barrel you can buy, so much pwnage
The best type of paintball for the 98 series is a mid grade paint (anything around 60 dollars like Diablo All Star). As for any gun, you don't want to just buy the cheapest paint possible (monster balls) because of the poor consistency and tendency to bounce after impact, but too high quality paint (easily breakable) in a Tippmann will chop a lot of paint.
There are many different types out there; folding air though, fixed, telescoping to name a few. Take a look around and find what works the best for you.
There are 3rd party builders who will do such a thing. But your best bet would be to take it to a local paintball shop.
Tippmann
none, paintballs do not fly far enough or are accurate enough to make any kind of precision aiming devise usefull
68/4500. high enough pressure for a Tippmann and just the right size.
There are a few website that you place a custom invoice design. The best place to try would be Fedex.
http://www.darksidecreations.com/ Their website isn't the best but they specialize in custom work, and they are based out of Calgary. Or you can order Polymorphe from their catalog (none in stock) from Barbies shop but there they have some pretty ridiculous mark ups.
If a custom van is what you are looking to buy, the best place in the San Diego, CA area would be, California Conversions. They have a wide variety of custom vans to choose from.
That would depend on your cultural and recreational preferences, and the proximity to your workplace. Some consider the Northwest quadrant of Calgary to be the best, while others prefer the Southeast, and others prefer to live in the Core ( downtown).
The best place to find custom plastic trays for your business would be to visit a local print shop and see if the surface of the tray would be able to be printed upon.