Well the Silverline SR-17s would probably be an excellent choice for the Portal, about as close to full range as you'll find in a monitor. The Von Schweikert monitors aren't in the same league as the others on your list IMHO. Yes I owned the VR-1s with a Portal Panache. The Silverline SR-15s would also be a good match. Oops, disclaimer time, I have a pair of SR-15s for sale here. They are the best monitors I've owned and I've owned more than a few.
But to be honest, if I were looking in your price range I'd go for the SR-17s.
But to be honest, if I were looking in your price range I'd go for the SR-17s.