Hiya NoPSI.
Sounds like a damn fine swap.
My 2 cents worth, the bottom arm needs to be the same length as the steering arm, otherwise , as Erol pointed out, you'll get bumpsteer that you cant fix with spacers.

Moving the holes in the crossmember outwards may mean you end up with a steering arm longer than the suspension arm, and no good will come of this! (try fixing bumpsteer in a mini some day)

Consider moving the top of the strut inwards to give yourself more camber, it doesnt give you as much increased track, and wont mess your bumpsteer around as much..

Having said all this, bumpsteer is usually the last thing to get tuned out of any circuit car, and with the high spring rates and limited suspension travel involved, doesnt make as much difference as on say a gravel car...

A little forethought now however can save you a lot of grief later!!