Ive been using a Trace Elliot GP7 SM300 for a few years now and am looking to replace it. Ive tried an SWR SM400 and was very impressed with the purity of the tone. Im looking for a used head with at least 300W and tube pre-amp, and was wondering what you guys and girls might suggest. I play a Warwick Corvette Std passive and, have Trace Elliot 4x10 and 1x15 cabs (both 300w rated at 8 ohms). Im looking to spend around 350GBP (550USD). Any suggestions and opinions welcome.