Now ditch that tuner/chip/programer/ 3position junk... If you don't know what it is, take it out. You run the risk of doing damage to the engine/transmission. I would do this ASAP.
You want to get a chip from one of the well known tuners, TW, PHP, Gearhead, P.I.S, etc. There are two main styles of chip that will get recommended to you, TS which is a chip that can be burned by essentially everybody, but the downfall is it must be sent back to the tuner to be reburned, or the PHP hydra is gaining popularity, the benefit of the hydra is tunes can be updated without removal from the truck. Really if you aren't going to go to single shot injectors, you don't need the Hydra.
I don't know much about banks gauges, other than anything with the banks line is generally overpriced, but if they are working keep em, if not autometer or ISSPRO should be what you look at. NOT glowshift.
As for low boost... is your turbo louder than it used to be? Do some research on sticking EBPV, if not check for boost leaks, you can google that too for answers.
I'm tired that's the best I've got right now, I'm sure others will chime in while I sleep