Whooo... Need any help spending all of that money you are going to be forkin out to build that D to be able to handle 24 PSI? Is that even worth it? Whats this company? I want one..!

You first need a HP goal, so you are not just throwing money away on stupid junk that gets you no real results.

Here are some facts, I wont tell you what I would do, ill just give you some facts and let you decide.

More displacement = larger HP/TQ gains from modifications.

D 1.6 with 125hp, boost it, and get 200hp. = a 75 HP gain
B 1.8 with lets say 125hp, boost it, and will get better results because of the displacement. It will be around 230-260. thats over double the stock HP, not exactily acurate, and I cant remember the conversion chart off the top of my head, but you get the idea..

I know this for a fact because I have help'd build both a D16 and a B18 for boost, and watched both dyno with about the same setup.

D 1.6 is cheaper, and easy to find, you can pick one up online or localy for around $400.00. And put $1,000.00 into it and it will be a fun little motor. And if it blows up you always have the one that you previously had in the car, and since you swaped the buit D into your car it shouldnt be a problem puting the old D back in..

Or you can go online/ or to a yard, and find a B 1.8 for $1,000.00 - $1,800, it is going to cost more because you need the tranny, and all of the other parts you cant interchange from the motor you currently have. And then once you have all that, and spent about $1,200.00, you will want to prep that for boost, and end up spending about the same amount aprox. $1,000.00. I have seen builds total to 1800, and some to 3200, -that is without the turbo setup, just building it up for boost. But it depends on the relyability you want, and the HP goal.