I went with the Bosch 330 horse in my truck with no pump mods. Cost was bearable, just under $500 installed. With other mods in sig, all poboy, I believe that it's making around 225-250 hp, maybe 500 ft#. The 330's smoke at full throttle at low speed (low rpm) until boost comes on. I tow a 5500# (wet) travel trailer and could use a little more power than I have, but want to conserve the stock transmission for awhile. (Till I win the lottery) GCVW is 13,300 - 13,800# and it manages most grades in cruise without coming out of O/D, running 60-70 mph. Still thinking about grinding my plate..... it issss a slippery slope. Mods so far have just made a good truck better, But the injectors are what really brought it to life. It was starving for fuel.
With the mods you have, go for the injectors. Watch for egt's to go up. Mine run 100-200* over stock, under load. Boost went from 17 psig stock on the governor to 33 psig on the governor now.
You didn't say if you killed the kdp.
Enjoy, Tom