I don't think there is any one "good" place to advertise. The advert scene is far too fragmented. I would start by knocking up a nice web page for it, with lots of photos, the usual rules about meta tags matching the body text, and making sure google indexes it.
If one googles for "XXXX for sale" one gets lots of hits, and from my business I find that most people these days hit google before reading any printed publications.
Re denial, I think there is denial around in both senses of the word. A lot of "common" planes are not fetching what the owners think they are worth, but also the less usual types (if in good condition) can fetch suprisingly high prices. There is certainly money around, in the £150k+ IFR tourer market.