Hi Michael
The Dimavery looks like a copy of the Grestch model, probably made in the same factory, haven't tried it.
I own a Recording King, almost identical to the Ashbury, except for the headstock (mine's not slotted). It cost 98 euros (Thomann), nice build, cheapo parts and the tone is quite on the dark side thanks to the mahogany construction and sorta hot pickup. You can do interesting things on it but I'd stray away if you want to go for a more trebly vintage style tone. You could always have a single pickup installed, should'nt be expensive (just have someone route the body and the rest is a piece of cake).
Also tried one that's very similar to the second link, made by SX. Very cheap HW and electronics, smaller size but light and sorta trebly, I don't particularly like humbuckers in lap steels. I definitely prefer the recording king or ashbury over that one.
Good thing about lap steels is that you can get them cheap on ebay and there's usually a few to choose from. You can find nice German lapsteels from the 60s/70s and some Japanese models around the 100/200 mark, you only have to make sure that they're in good condition but Ive purchased a few in the last few years for 100/150 euros and they sound great!
Oh yes, get a nice set of C6 strings on there! 8 strings better than 6
