There is a fundamental problem with wooden crossbow prods, which is why they weren't in use much. To get a lot of poundage from a short draw and a short bow is difficult.
I think you need a good wood or build the prod with some deflex so that it doesn't get over strained just bracing the darned thing.
Alternatively something with maybe a Bamboo back (Maybe bamboo back, belly and core... with maybe some extra bamboo somewhere
).
To get a high draw weight and it looking 'right' I'd go nice and wide, rounded back, enough deflex to take it to almost brace and bit of reflex very near the tips.
This is something that's on my 'to do' list and that's how I plan to do it.
Remember to make the bow slightly curved so it's tips sit higher that the centre, to stop excess string pressure on the stock/track.
Let us know how you get on.
Del