An e-scow is a blast to sail, (maybe while building your i550). It's 28 ft long, planes easily, is faster on every point of sail than the i550 but isn't for the faint of heart. You need 3 or 4 people who know what they are doing on-board when the wind is blowing hard (since the people are the ballast). It can also act as a party barge or a swim platform. We've taken out 8 people before. For its size, it is remarkably easy to trailer.
For i550 builders, I think that the Harken gear on the boat alone is worth a good part of the price, and while the trailer is a bit long, I think that it could be adapted for your nice new i550.
I had planned on keeping this boat, but it hasn't been off the trailer once since I finished my i550 a few years ago. The i550 is a way better boat, but you can't have more fun sailing for this price.
Phil