Wow looks interesting... the HE 4.9g servos would work just fine but you'll need to shim the mounts (no big deal considering what you are doing)... that goes the same for the cirrus. I'd try and shoot for a conversion weight of no more then 6-7oz wet... I haven't messed with glow in ages but I always thought this model would be a blast on an .010
A .049 would seem like overkill so your .061 is really going to move this thing if you can keep the weight reasonable.
-Bill