I would forget the webber and go down the Bike carb route
You should be able to use the 1.6 ignition system ( it's a basic electonic setup )
You can spend a fortune tuning a pinto... I would do the bike carbs and if you can find a seconf hand 4 branch then do that.
Then keep an eye out for somethign a bit more powerful.
One guy on the sierra forum has just had his 2.3 16V Bike carbed engine dynoed at over 170BHP ( NAT ASP ) which aint bad , and there's more to come from it. Look arround arround and these engines turn up cheep.
TT