Gulfcoast Conversions in Houston does excellent work on vans. They would be my first stop if you aren't up to do it yourself. You can visit their website at:
http://gulfcoastconversions.com/gccsubsite/ford.htmlIf you want to keep it a bit more simple - large vans are quite easy to work on yourself. I am a novice with just a little background working on boats, etc - but I have installed new stereos, speakers, USB chargers, back-up cameras (among other upfits) on three of my Sprinter vans. I currently have two Sprinter vans. One I keep here in TX which is my daily driver and I have outfitted for surfing and camping. The other is an older Sprinter that I keep in California and is also outfitted for surf expeditions and camping.
Texas Sprinter (2013 Crew Van) - I installed a new double DIN head unit on this van, installed a back-up camera, ran two new speakers to the back doors, installed a sub and amp (small prepowered sub from rockford fosgate to just round out the stereo a bit). I also built a lofted bed in the back, added some lighting, installed a swivel on the front passenger seat and am in the process of finishing the exterior. I have the alumines lightbar and ladder. I will soon have a full top rack from Aluminess too (so I don't just have a ladder to no-where!) I am going to install lights on the light bar that will help out a bit on dark roads. The standard non-HID sprinter lights just don't cut it when you get off the beaten path.
California Sprinter (2006 Passenger Van) - This van was priced great and was low milage (the pre-2007 models have a 5 cyl diesel which can run forever. I took out the two back rows of seats, installed a lofted bed, build a storage system under the bed, installed a new radio head unit, installed all new speakers, installed the same pre-powered sub from rockford fosgate (PS-8 I think...) and then added a few more creature comforts for surfing Southern California or posting up in a camp site in Northern California.
If anyone has questions regarding Sprinters feel free to hit me up. I have had three of them (two of the older T1N models and one of the newer models) and have been very pleased with them.