One of the sources for ECI kit engines that you might consider is
http://www.lycon.com/
Kenny Tunnel is the owner. Here in California many experimentals (and certified planes) are flying with Lycon engines.
In my case I purchased an IO-320 mildly leaned on. It put out 202 hp on the dyno. Kenny ground runs each new engine 5 hours on their dyno and you get a computerized print out with a number of interesting parameters.
I can go fast and burn 9.2 gph at 7,500 feet or slow down to 160 and burn 4.9. I prefer to go fast.
At last years Reno Air Races, Lycon engines were running in 27 racers....Shawn Tucker has used Lycon engines for many many years.
I just talked to Kenny today and his business is still running a back log which to me shows that cream always rises to the top.
If you can't go full boat on a new engine, you just might find a way (if you're not in a rush) to get something that will be very special and not break your bank account. Kenny is a good guy and if you get an opportunity to talk with him and tell him your situation, you might be surprised what you can work out.
I know this sounds like a commercial, but when you work with a quality company like Lycon, you want everyone to know what fine folks they are.
Tom Hunter