Speakers for low power amps?

Just being nosy, but why do you want to give up the system you have? It looks like a really good system.

Have you considered keeping the amp and speakers, and going with a good tube pre-amp like a Herron VTSP-1A/166 or VTSP-2, Conrad-Johnson Premier 17LS2, or CAT?

Reference 3A Di Capo's are really nice for an SET set-up if that's what you want to do

There are many options--any of the single driver speakers--along with many others---Just stay away from speakers that drop below 6--at any point (many speakers say "8" but may drop to 4 in the bass).

Krell man, I like my system but I like to listen at lower volumes. The Aerials don't really open up unless you turn them up. I found my friends 10t speakers to be the same way. I feel it is time for a change. I will look into the REF 3As. Anyone else that have specific models for me to check out?

I'd recommend speakers with a nominal impedance of 8 ohms or above, and without any wild swings into the low impedances.

For amps of 8 watts or more(like 300B), I recommend you select speakers with 93db/watt or higher sensitivity.
For amps of 3.5w - 5w(like 2A3) I recommend speakers of at least 96db/watt.
For amps of 2w(like a 45) I recommend speakers of at least 99db/watt.

Drivers like Lowther, Fostex, AER, REPS, Diatone, Coral, and similar single-driver speakers work well with SET amps, and are often used. Front horn, back horn, or TQWP setups are common.

Some commercial speakers that a commonly mated with SET amps are Cain & Cain Abbey, Beauhorn, Lammhorn 1.8, Lowther(various models), Oris horns, Avant Garde horns, Klipsch horns, etc.