I haven't tried the VT100 with the D38, but I used to have my D38's with a pair of Cary 805AE's. It ran the D38's OK, but my more beefy CAD-211AE's ran them even better.
I have also tried the D38's with my Pioneer A400. It's a different class of amplifier - 15 years old, integrated SS, 75W (c.f. 110W for the 211AE) and AUD$600 when new (as opposed to the AUD$22,000 CAD-211AE!). It was thin sounding and dynamics nowhere as good as the CAD-211AE. Totally unfair comparison, but I did it because I had the equipment to hand and was curious.
I think the VT100 should be a good match for the ProAc, but that's a wild guess. ARC sound is very neutral (or "sterile" if you are not a fan). If you are looking for more of the same type of sound, look elsewhere. If you marry the two, I am certain that the ProAc sound will dominate.