Your best bet would be to find a specific paintball shop or field. Canada is known for its field and shop called "The Badlands". They should have everything you need.
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.
The best place to purchase custom football jerseys is Logossoftware, or MyLocker. From these websites, you can custom make your own football jersey in the style you want.
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.
The best place to order custom recognition pins is the popular online shop Pin Mart. They specialize in pins and have tons of great deals on custom pins.
Anywhere that is an official paintball pro-shop. Maybe certified by Tippmann or any paintball company.
There are a few website that you place a custom invoice design. The best place to try would be Fedex.
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.