Vesalia are still around and seem to have quite some stuff left in stock.
I have bought various items from them during the last 4 years. Their delivery time ranges from ten days (Germany to Greece) to... umm it did get real bad once

They also tend to include gifts in the packaging such as CDTV t-shirts (nice one guys!), Amiga pens, stickers etc.
They seem to answer only emails that refer to orders, not other enquiries, and even then they are a bit slow in aswering (4-5 days minimum).
I've talked to the owners (Oliver Does and his dad) over the phone and they seemed eager to discuss Amiga matters.
When ordering make sure you tell them to pack the stuff real well - last week I received an A1200 and they had crammed an A4000 keyboard in the A1200's box as well which resulted in a really bad scratch on the A4000 keyboard.
All in all I think they are ok (especially considering the state of the Amiga market) and I'll definitely order more stuff from them.
As for the rest, there's Amigis and KDH and some others. I did order some stuff from Power Computing a few years ago and they delivered pretty fast. A friend of mine though, received a dead A1200 from PowerC and they have not responded to any of his emails so far.