I've got a few, an Excel UHF and a pair of Elan VHF radios. The stock Tait adapter is actually two parts...a RJ12->DB9 cable (or RJ12->USB, available on ebay from seller bluemax49ers, also used to program the Tait 2000 series of mobiles), and the TOPA-SV-003G lead that connects to the back of the radio. I was lucky enough to score one off an eBay seller, but they do not come up often. The version I got also does not connect to my Elan's...Tait changed the latching mechanism slightly between versions.
There are a few ways to get the radios programmed without the -SV-003G lead. One is to acquire a car kit, which has a DB25 port that exposes the programming lines, and build an adaptor. The car kit TOPA-VK-002 does come up on ebay occasionally, and was also used for MA/COM Panther 400P/600P radios. The other way is to get a RJ12 breakout adapter, and manually hold the leads to the correct pads while reading or writing the radio. This is how I program my Elan units, and while it's not ideal, it is not nearly as painful as it sounds. The service manual is readily available in PDF format online, or I've seen print copies on eBay as low as $5.
A few pictures by way of illustration:
Using the breakout to program my Elan



The elusive TOPA-SV-003G
