I thought very seriously about getting a string mower before settling on my 128djx and did not find any of any brand (besides DR) that offer a metal blade. DR sells a thicker .175 diameter line through their site that might hold up a little better than the .155 line, but I think that's your only other option short of jury-rigging the shaft on your husq trimmer to accept a DR head and then using one of their attachments*.
How do you like your husqvarna trimmer? I've only ever used a swisher walk behind and loved it.
*This is probably a terrible idea.
Lowes usually carries string in that size. You can use the precut stuff sold under the Swisher name or just buy a roll and cut it to the size you need.