I'd say you might be very happy with a Sumiko Blue Point Special at $350. It would mate well with your rig. It's a high-output MC cartridge, and is very good. If you don't mind changing cartridges, I would recommend buying 2 cartridges as you start out. You could buy the Sumiko and a low output MC, such as a Benz Micro Glider L2, and stay within your budget. This will give you a chance to decide if the EAR is better with high-output MC or MM, or with low-output MC. Since EAR make a step-up tranny for use with low-output MC, you may find that you like the Blue Point special better than the Benz, at half the price. Then, you can decide later on to invest in a much more expensive MM/High-Output MC, or to buy the step-up tranny for Lo-MC. You'll also get practice mounting and aligning cartridges! A valuable skill if your gonna be serious about vinyl.
Happy Listening
Happy Listening