I've been talking with some makers, players and sellers of electro acoustics. The big problem doesn't seem to be the jackplate, but that the sides should be reinforced around the jack. This would require taking off the soundboard which I'm not very interested in. Best compromise is probably a chinrest with integrated jack.
The main reason for all this is the aestethical issue. I wan't the instrument to look electric. I'd like a volume knob in the soundboard too but I've dropped that idea because I'm not willing to sacrifice the acoustic tone. First I had the idea of an opening on the backside, then it would be easy to attach the volyme knob and reinforce the ribs, but it's a bit troublesome to make such thing on an arched bottom and besides I might damage the acoustic tone. The fiddle looks a bit like old jazz guitars or some semi acoustic Gretsch or whatever. It has a bit of rockabilly look to it and my idea is to go somewhere that way. I want an electric with full acoustic tone, not an amplified acoustic... In the future I also intend to replace the pegs with machine heads.
http://www.sdc.org/~acahay/booklet.html, see the bottom of the page.