Need advise on DAC purchase 220v/50Hz

I currently have an Arcam CD82 feeding into an Arcam AV8. I wish to improve my CD playback but have a limited budget (about $2000). My main options at the moment are as follows, I am based in Ireland and the following are the selection & prices currently available to be:

Used Musical Fidelity A324 DAC ($800)
New Bel Canto DAC2 ($1600 approx)
New Musical Fidelity Tri-Vista 21 DAC ($1800)
Used Meridian 506 CDP modified to 24 bit ($950)

Possible modification to CD82?

I would appreciate any advise on the above options as to which should be best value for money, best result or if I should wait until I have enough money to get used Wadia 301/302 or similar.