I looked into this sort of thing about 4 or 5 years back. From memory, I think the E15 rods are 133mm centre to centre and use a 40mm big end journal size (rather than 45mm on a-series). I was going to use E15 Turbo rods as they were beefy looking forged jobs.

The costs and difficulties associated with offset grinding turned me off the idea. Oh, and it was about that time that we stripped the race A15 and found two cracked journals, so the idea of machining them down 5mm sounded about silly.

Have you thought of running the E16 crank?? I think its stroke is 88mm and will negate the machining process plus suit the e-series rods perfectly. I haven't tried an e-series crank into an a-series block so don't know what difficulties, if any, you will encounter.