new 06 f550 needing suggestions to increase reliability

[06f550]

Ok Im a newbie, I have been doing many searches on both this site and others looking for the proper mods to preform to my new to me 06 f550. I am not looking at building a dyno monster, and honestly the power is just fine, this truck is a service truck I am using in my buisness and I just need it to be as reliable as possible. The truck is equipped with a 6spd man trans and is 2wd. Current milage is 101k so warranty is not a issue. I did have a oasis report done before purchasing the truck which showed regualar maintence, and the replacement of 1 oil rail plug.

From all that I have read a egr block off/or removal would be a great addition. I have spent alittle more than I would have liked on some updated tools and this truck and equipment so funds are rather tight at the moment. Can I get by with just a block off for now? Also the truck still has the factory exhaust on it with a cat, should I look (I cant really find any exhausts for a f550) just replacing the cat with a pipe or a complete exhaust? I really dont need much more power but a very mild tune from sct that would help with any codes from blocking off the egr would that be advised? I mainly dont want to have to purchase head studs any time soon so as close to stock as possible is what I would like to keep the truck, but the egr worrys me alot, this truck doesn't tow anything heavy but it weighs just a hair under 18k lbs fully outfitted. MY biggest concerns are improving reliability and then any fuel economy benifit would be welcomed, any power that come with the mods i perform for the 1st two concerns would just be a bouns. Also theres no smog testing or inspection stations in my operating area. Thanks in advance for any help.