Use a sligthly thicker headgasket when you recon to lower the compression and allow you to run a bit more boost reliable on the TD12. Thats what I'd do anyhow
hybrid grant was running 14s on his 351bhp starlet and it didnt seem any worse than what i would expect he did have a quaife however. There is no benefit to it though so i would run 15/16s just for stability really and yes you will be more prone to torque steer as a TD04 coming on boost is alot more violent than a hybrid.
they look tidy mate, are exactly the same as the 14s that were on the mk1 when i sold it, saw it down lakeside a while back still looked and sounded well the owner didnt seem to have a clue though.