Keyboards with keycaps which are the same shape

Hi.

I'm new to this list, apologies if there's already a discussion about 
this topic (if there is, could you point me to it, please?).

I'm trying to source keyboards that have keycaps all the same shape, 
for conversion, primarily to Dvorak (I've started recently to sell 
these, with some small success so far) but obviously such keyboards 
will be of interest to anyone who wishes to try an alternative layout.

I have so far found just three keyboards that are reasonably priced 
and fit the bill. These are, in order of my personal preference of 
quality:

1. Logitech Y-SU61 Deluxe 
2. Tesco 'Value' keyboard
3. Colorsit KB-1807 

(#1 and #3 are available through my 'Broadband for your Fingers' 
eBid.net store at http://uk.four.ebid.net/perl/main.cgi?mo=user-
store&title=Broadband-for-your-Fingers - the Tesco one costs just 
£4.45 from - surprisingly - Tescos).

These are all PS/2 models (which possibly explains why such keyboards 
have become so inexpensive in recent months?). I have been trying to 
find some USB equivalents, even though these are likely to be more 
costly. 

Does anyone here know of any such keyboards, PS/2 or USB?