I have installed a number of Holley EFI systems, but it has been long enough ago that neither of the shown systems were available at that time. I worked directly with the EFI guys at Holley because I did the very first installation of a pair of their 4-barrel units on Brother Lon's '67 Mustang/427 TP. We were learning as we went. The Holley guys were VERY helpful as we worked ourselves through the maze toward having a fully functual set-up. I was writing for Super Ford Magazine and getting things right resulted in several articles for the mag.
From your description, I'd follow the info above and go with the 'better' system. Keep in mind that having better than you think you need is likely to be of benefit when the inevitable improvements become desirable.
KS