I think I too would go for the 2228, as you say, it's a small price difference for the extra performance.
You should also be able to control the flowrate of the filter (?) because you may find that the flowrate is a bit quick for your tank.
The 'optimum' filtering turnover figure I see around here is "5x" per hour, so working with the figures from Jim:
The Eheim 2227 is rated at 227 gph and for tanks up to 90 gallons.
The Eheim 2228 is rated at 273 gph and for tanks up to 160 gallons.
Your tank 65 Gallons
2227 = 3.49x / Hr
2228 = 4.2x / Hr
So that would confirm it for me, I'd go for the 2228.
(Just to confuse the matter, I don't know how Eheim quote their flowrates as I can't find the info on it, but it seems to be a 'market trend' that external filter flowrates are quoted without media, and at 0 head, (so effectively the PUMP flowrate, not the FILTER flowrate), so you will likely get flowrates less than those given above once it's actually on your tank. However, the 2228 is still a better filter in terms of turnover and a small cost difference

)