While the 355 will sound great I think you will find it disappointing compared to the 1M. In early September I went to a national Ferrari event with my brother. It was a four day event and he drove his 575 Maranello and I drove my 1M. There were multiple 355's, 360's, 430's, a few McClarens, one 458, one FF, one 599 and a number of Maserati's. Over the first two days we drove about 600 miles through the back roads of NW Arkansas. It was great fun and never was the 1M anything but comfortable and stable. We parked for lunches and dinners and I had more people want to talk about the 1M than almost any of the less unique cars like the 355. I was surprised that after 4 days I left not wanting a Ferrari.
I think the 355 is a bargain for a 15 year old car. I think technology has improved so much in those 15 years though that it would soon feel old and you would wish for the comfort of the 1M.