Your preamp and amp form the foundation of a very good system.
Given your objective to build a high-value system, and your plan to buy Vandersteen subs, you should definitely consider a pair of used Vandersteen 3A's or 3A Signatures. For value, this speaker is very hard to beat, and it will perform wonderfully well with the matching subs. Like you, I have a strong value orientation toward audio and video equipment, and I have been extremely pleased with my Vandersteen system.