As far as your Marantz against the Parasound Halo integrated... yeah the Parasound is better but not by much honestly. One of the shops here in town carries both lines so I know both pieces. If you didn't already own the Marantz then sure go for the Parasound. The Parasound is a very nice full featured unit - Swiss Army knife for an integrated amp for sure.
Someone mentioned ARC VSI60; now that would be a nice step up. No comparison between the Halo and a VSI60... ARC here all the way.
Again get the Vandy's first and give your Marantz a try. Get to know the Vandy's first or you'll end up chasing your tail and later wondering how the heck you ended up with a pair of Wilsons wishing you still had your Vandy's. I had a set of 2Ci's I ran with a vintage B/O receiver for a short stint which sounded stupid good using that receiver. Heard a lot of Vandy's over the years and never heard a set sound bad regardless what was on them.
Wish I kept my set. Mine had the beige socks which I thought looked great on them over the black. Thinking the wood was natural walnut and not the oak. Had the Sound Anchor stands. I'm wiping my tears...
