What can I expect from Klipsch RF-7 w/small tube?

I found when I tried the 7's the bigger driver gave a little bigger sound, but the RF-35's had much better punch with the 8's that they still use in the new lines vs. the 7's with 10"'s being eliminated.. The Reference series to me and my friend which still owns them always seemed to be better with the 8" drivers, also this did help smooth out the mids with Voice etc.. I suggest looking at the new Klipsch with the Triple 8's vs an old pair of RF7's and use your intergrated, it will probably be very nice with good bottom end.

Sorry missed the spike question, this is hit or miss, it will tighten up, but without spikes in my experience can have more full feeling.. The only one so far that has improved both Room feel, and Tight punch is the Audiopoints from Starsound, they are pretty pricey, but pure brass and heavy. They seem to transfer the most energy and cause them most solid image with clarity at the same time. Most other spikes I have heard are a bit dull, or simply make the speaker lose some body and become just sharper. Whether this will be the same results on every speaker, will be your own experimentation. Starsound does give an audition period with a full return policy I believe.

Spikes can make a big difference, especially on the shape of your bass notes. Really clears them up.

Try the spikes first, they will make a big difference. You have very nice speakers, if you don't have the low end of bass you desire have you thought about adding a powered sub-woofer?

I run my Klipsch Chorus II's and KLF-20's (series right before the Reference Line) with my little 14 watts/ch Eico HF-81. Klipsch speakers match up very well with tubes and because they are very efficient, they don't need a lot of power. The 14 watts/ch on my HF-81 provides enough power to get my speakers to ear-bleeding levels if I wanted (room size is 15W x 20L x 8H).

Smaller woofer size is going to give you better bass punch than larger woofer size. If you do end up getting Klipsch speakers (any Klipsch), upgrading the crossover networks is a MUST.