Hopefully this will help some. My heads still spins if I think too hard about all the options for EFI but it would do the same thing with carbs..
The way I see it you have 3 options.
1. Buy the Quarter horse and tune it yourself. There is a learning curve but since your keeping to stock values (for now) and just killing the EGR & vacuum canister you can do this easy enough (uncheck and option then save/upload). The tuner pro software is free and I found it easy just to do small changes like turning stuff off that wasn't needed (I know that software can do more but I never spent the time to figure it out, I am a beginner with EFI).
For the power increase you will need to get deeper into the programing and analyze data logs. I'm not for sure if the Tuner pro allows data logging/play back but it's been a while since I looked. I highly recommend the Binary Editor software
http://www.eecanalyzer.net/product_info/binary_editor.html it does everything and is simple. I really like the dashboard to view your engine real time.
they have the EEC analyzer for data play back. There is a cost but after using EEC Editor I would suggest paying for the software (IMHO don't get EEC Editor Software from Paul Booth).
Good thing is if you want (with QH already installed) you can still go with option #2 and have a pro get the HP out you want.
2. Buy the Quarter horse and pay a shop to do your tune. There are a lot of professionals that will send you a tune file and then you send logs to them to analyze and make it work. Once you get those files you upload them to your QH and off you go. Most of the shops do like using Binary Editor as it is the best software out there, but not a requirement talk with the different shops.
This link will get you a list of professionals to start with.
http://eectuning.org/forums/viewtopic.php?f=3&t=16907&p=105104&hilit=professional#p105104 The EECtuning.org forum will give you a lot more information (it does help keep your head spinning but is useful). Some of the information you take with a grain of salt as it applies to blown and race engines.
3. Buy a tuned chip from some other place. It is a good option but when you want changes to it normally you have to pull the chip send it back for a new tune. Of course the new tune/programming will cost. You normally don’t have data logging with this option.
I do think the QH is a very good option plus it gives you more control when you’re ready. The data logs are a very valuable tool one that takes out a lot of guess work.
It does look like there are a few of us here the like the EFI route. I know not standard but hey it’s our trucks.
