Take a look at our Files section, Mods, Horizontal Smoker Mods, etc. etc.
Lots of good info that came from some other sources - lots of us have or have had horizontal (New Braunfels, OK Joes, etc.) cookers and so we have these pages -- lots of help and hints on baffles, etc. :D
I've got a NB horizontal in my menagerie and it cooks fine - I've just gotten to where I use my WSM a lot more. I made a simple expanded steel charcoal basket (quick and dirty with no welds or wire - just cut and bend) and a 20-something gauge baffle that sticks about 10" into the horizontal chamber.
Good luck - with this and the job!
Southern Brethren BBQ Competition Team
"It's all about getting paid!" - Myron Mixon
"I love being hated in my hometown!" - David Hair
KingFisher Gator Rotisserie cooker, WSM, Stainless 5 burner with IR gas grill, Turkey Fryer, Weber JD Commemorative grill, slightly used Bandera chamber for future use as a cold smoker, Masterbuilt 40" insulated ELECTRIC smoker