I went the 207 route and after having that setup for awhile I wish I would have gone with the 2.5 block to start with. I went with the 207 as built blocks were having alot of issues when i was looking to upgrade and I wanted a nice oem smooth motor. The 207 is an awesome motor and is smooth but it doesn't spool a big turbo like the 2.5 does.
Something recently broke in my ej207 over the weekend so I will be tearing it apart when I have time. I am looking into a 2.5 block to go with the jdm heads. I should have a nice writeup to compare the differences when I am done. Most likely won't be until winter time when I have a break from school.