Does anyone know where to get 5.4L longtube or midlength headers? I found one pair for 900 and that's way out of the picture. How about any comments with shorty's. I was told i need to find mid lenght or long tube but does anyone have anything good about shorty's and where i could get the best for the best price?

99 SCab 4X4 sport Dual exhaust 34" Buckshots Diablo sport chip

 

Most long tube headers are designed for 2-wheel drive Lightnings and none are cheap. Here is what little is available for your 4x4 application (don't faint when you see the price).
http://www.secureperformanceorder.co...ord_truck.html
There are various opinions on the benefits of shorty headers on a stock to mildly modded, normally aspirated 5.4. I tried 2 sets on my 2000 5.4. My opinion is that the improvement is marginal at best. If you were running an aftermarket supercharger and had a complete, custom, mandrel bent exhaust system designed, I'd suggest long tube headers or nothing.

 

in the hotrod magazine they did dyno test on a 5.3 chevy cast iron vs shorty headers. They gained 10hp at the flywheel... Thats hardly anything.