Advice on Mono-Blocks without breaking bank

Current System:
Odyssey Labs HT-2 (a Stratos knockoff)
Audio Research LS-8 Tube pre-amp
Rotel Cd (as transport)
PS Audio Digial Link III DAC
Kimber Kable Silver Streak interconnects
Acoustic Zen Adagio speakers

The zen's are new and sound great, think of mono-blocks as next improvement (unless you think go pre-amp first,love audio research products)

so... Go to Odyssey stratos mono's or go "d" to channel island d200? This class d technology sounds interesting, have all types of music from rock to mozart.

Thanks Much in advance