I have used Heresys which actually fill your outlined description if you are looking at the original or first series speakers. You won't get a lot of bass. If you aren't going to play them loudly and you listen fairly nearfield the world is your oyster. Remember most amps from the "golden age" of hi-fi wre el-84 based. Right now I am using a Fisher 400 receiver, that uses 7868s a close relative to the el-84. I happen to be using Hyperion 585s to good effect. If you want to fil;l a big room then sensitivities in the 90 DBs/W/M are in order. I have old LaScalas that will do it and old JBLs both of which were designed for power like this. They exceed your price limits and to be very honest bass performance from these speakers is not great. You may want to use a powered sub to help the lower octaves fill out.
Jolida 102b Speaker Recommendations
I recently acquired a Jolida 102b tube (EL84) integrated amp. Factory specs say it is 20 watts per channel, some say a bit less maybe 15 wpc. Looking to hear from anyone who has owned/heard this amp with speakers that were a good match for this amp. I have read that the Klipsch Heresy speakers are a good match. I would prefer to go with a vintage speaker if possible, but will consider anything used under about $500/pr. I am somewhat handy with speakers and can refoam drivers and upgrade crossovers. Thanks.