I agreed with your thinking regarding the purchase of the used Vandys. This will allow you to experience the Vandy signature sound (an yes the new version will provide more of it with greater detail) while providing time to consider upgrade options. Sorry about the Marantz issue, I also thought using it was a good choice.
Given that you are happy with the used Vandys, I would focus on an integrated that mates well with them. You might consider purchase of one comparable to your Marantz on the used market for the short term to allow time to assess the Vandy sound. One concern is that when it comes time to upgrade speakers you might find ones you want that have a different sonic signature and represent a different load to an amplifier. Thus not the best for your 'current' amp. Of course this would not be a problem if you choose the Vandy II sigs. Buying use will allow you to replace components at minimal expenditure and buy you time to make best choices down the road. Hey, you just might keep the used Vandys for some time.
Given that you are happy with the used Vandys, I would focus on an integrated that mates well with them. You might consider purchase of one comparable to your Marantz on the used market for the short term to allow time to assess the Vandy sound. One concern is that when it comes time to upgrade speakers you might find ones you want that have a different sonic signature and represent a different load to an amplifier. Thus not the best for your 'current' amp. Of course this would not be a problem if you choose the Vandy II sigs. Buying use will allow you to replace components at minimal expenditure and buy you time to make best choices down the road. Hey, you just might keep the used Vandys for some time.