glad to hear it
i may be wrong here but i'm pretty sure the hubs (not that they are relevant) and the stub axle from the series iv and v alpine are the same as the tiger. you then bolt some MGB steering arms to the stub axle (which are cheap) after filing out one of the holes a little and making a small spacer about 5/8" thick to offset the arm against the brake caliper. you can use alpine tie rod ends in the (reversed) mgb arms. and, yes this also fixes the ackerman angle as you pointed out.
if you have a series i to iii alpine then it's probably worth finding the front suspension from a later alpine.
have you considered a ford cologne v6 instead of the rover v8? loads of people have done that conversion which is a very nice fit. there is even a kit for it. of course if you fancy the engineering challenge of doing it all your self with the rover v8 then good for you! the exhaust headers will be quite tricky. will you be making them yourself? i've always thought something like a modern ford focus engine would be great in an alpine!
also, if you don't already know the saoca.org forum has a lot of active posters with converted alpines, though being american, they are probably not too familiar with the rover v8.