@rfc, how big is your room and how loud do you listen?
Unless you are filling a very big room or play your music at concert levels, you might not need so much power with the Spendors. I've got D9s and in a 12x17 room and driving them with a Pass X250.8 I never once it had it leave its ~18w Class A bias playing in the mid 80 dBC range. I then switched to the XA30.8 and could play it in the mid 90 dBC range without it leaving its 30w Class A bias.
You might be able to save some $$ unless you specifically want a high powered amp...; one of the many virtues of the D series I really like is it doesn't require an uber-amplifier to make it boogie or sound good.