Hi Allan,
Bill is right on target.
The Impact ARC is excellent. If UHP has one, contact them ASAP! After flying with Paul and watching him fly his ECL Impact at several contests, I called UHP. I love mine, it has a Plett. motor just like Paul's 1st and 2nd one had. The UHP ARC is beautifully made, light and strong. Very easy to convert to ECL.
Randy's wonderful SV-11 is also a great choice, but I don't know if they are still available? I have one of his ARCs and it is a very nice plane. I have a Hacker 40S in mine. See the complete ECL conversion thread here on SH in the E section.
I also have the well designed, and great flying, T-Rex ARC. These are still available from Brodak's website. There is a very complete ECL conversion thread for this plane on the "Getten ALL AMPed up" section of this SH Forum. This thread also shows how to do the few (minor) wing mods and fuse. mods, that help the plane live a long healthy life. :-) ...... (NOTE: This is an excellent flying, and well designed plane. To keep the plane light, the designer called out thinner wood parts to compensate for the very heavy/strong balsa that was being used on early CL ARF/ARCs. Unfortunately for the designer, his plane was the 1st that got the new lighter/better balsa that is used now. The mfg. did not tell anyone of the change. The plane is very light, which is great, but it just needs a few braces in the fuse, and in the wing center spar area. The thread shows a great HOW TO on this easy mod. This plane is the easiest to convert to E power. It also looks like a P-47 WWII plane.)
Brodak also has the ARC Vector 40 (it's a smaller, 40 size version of the SV-11) and the ARC Legacy available and in stock now. These are both good planes, I have the Vector but I am not familiar with the Legacy, other than others seem to like it a lot.
If you go to the Electric forum here on SH, click on the very top of the forum where it says SETUPS. You will find many different E power systems for all the above ARCs.
All the planes above have won many Nat's trophies and are very competitive. Paul's IMPACT of course has both World and USA Nat's. 1st place trophies. Watching Paul fly his Impact, is like watching a great artist draw perfect figures on a bright blue canvas with a very nice looking paint brush. :-)
I like the ARFs for all my ERC planes. They are all made for E power and thus are easy to set up. I like to use ARCs in CL planes because I find them easier to modify for ECL and to convert them to have the wing come off, like our RC planes. There are several informative threads here on SH showing different ways to make take-apart ECL planes. My guess is that you already have many good ideas on how to do that already. ;-)
Good luck with your search, and please let this ARF forum know how it all worked out. :-)