Hi Peter,
Logic developers use the Abatron BDI2000 JTAG to develop LogicLoader on all of it's products.
http://www.abatron.ch/
http://www.iar.com/
ARM Multi-ICE and IAR are also tools that customers have had success with.
http://www.arm.com/
If you are looking for a more basic and cost effective tool then I would check out Macraigor. Please keep in mind that these tools have been known to have issues at times. To the best of my knowledge they have resolved these issues with our products.
http://www.macraigor.com/
Cheers,