I have the following bars for my 50cc saws, all are .058 gauge as that is all I use in .325 pitch:
Husqvarna laminated 18" (HL-258-72) - have had this on for 27 years. I've un-bent and un-twisted it, dressed it, and it still works great. They don't make 'em like they used to.
Oregon Pro-Lite 18" (188SLGK095) - this is a laminate like the Husky above but with a wider nose profile. Bore cuts better, slightly heavier with a better balance. Also have this in 20".
Total Super Bar 18" - virtually identical overall dimensions to the Husky. Looks like Tsumura just took the outline of the HL-258-72 and made it into a solid bar with a replaceable nose sprocket. This definitely looks the best on the 545, the brushed steel is very sexy.
WoodlandPro TimberMAX Lite 20" - laminate with a wider nose profile, not the most rigid bar. Only used for a few cuts. Will probably sell this one.
Carlton Speed Tip 18" (18-01W-K272-ST) - recently got 2 of these new, have not tried them yet.
My favorite for looks is the Total/Tsumura. My favorite to use cutting wood is the Oregon Pro-lite. Least favorite is the WoodlandPro. Can't wait to try the Carltons.