I've been brewing with rye somewhat frequently as of late. A porter with rasberries and dark malts will almost certainly overwhelm the flavor of the rye. If I were in your shoes I would probably do a rasberry roggenbier. Maybe 30% rye malt, 10-20% wheat, 50% 2-row, and a bit of Munich (~1 lb or so per 5 gallons) and even maybe 3-5% melanoidin. 1/2 can of this stuff
http://morebeer.com/view_product/16731/102194/Raspberry (I just made a hefe (5 gallon batch) with a full can and it was WAY too much). THen hop it to 20-30 IBUs with hallertau or something similar. You could even stick your neck out a bit a make it an imperial rasberry roggen. I like the idea of the rasberry and rye, sounds like a good combo if it has to have the fruit. Good luck!