With the Lancia D24 in mind you're definitely on the right track! Though I'm not entirely sure if it should have a snout exactly like that. Looks a bit like it's vacuuming the road...
A bit more upright would be better I think.
200 bhp won't be a problem at all when using the Scimitar chassis. There are lots of owners who converted their Scimitars to a Rover or Chevy V8 for instance, some even with twin turbo's on them... (have a look at
www.sporting-reliants.com for inspiration)
I've also been thinking about a name for the Scimbased special. I agree that a type of sword would fit very well. It's both true to its origins and has a nice sporty, somewhat agressive ring to it. Pity that "Rapier" and "Sabre" are being used or have been used for cars already. The Sabre actually was a sportscar produced by Reliant btw!
May I suggest "Spada" spyder or special? Still a sword and in my opinion it compliments the Italian look and feel of the car.
Gr.,
Scimmy