Yes, Stewart of Reading are very good. I bought a couple of items a few years ago from them.
However, one aspect of their (excellent) service is that they insisted on testing each item before it was released. I chose to buy at a busy time for them and there was a backlog. So I had to wait a couple of weeks before they could test the items. They really do like to make sure the items are tested and working before release!
This was a bit frustrating for me but I had a very pleasant surprise when the items arrived in the post. Not only were the items carefully cleaned (I could tell they had been cleaned) and well packaged, they also included bound copies of the user manual as well for no added cost.
So it was definitely worth the wait
other suppliers I can recommend are:
KJDS (advertises on ebay and on here)
Ralfe Electronics
Ex rental deals from Microlease/Livingston Hire