I spent a whole year researching the differences between all of the different brands, and there are more differences than you would realize at first glance. Things such as straight stem vs tapered stem, round or chamfered interior of the femoral cap, different coatings for bone ingrowth, cemented or cementless, different thicknesses and clearances, different size ranges, and the endless controversy over whether "heat treated" vs "as cast" really matters. Places such as the Australian Registry will give you a listing of failure rates with the different brands over thousands of cases, but it is difficult to separate out the factor of the surgeons' skill, experience and training. None of us on this site are really qualified to give advice on this, so I think your choice is whether to pick a surgeon and go with his recommendation, or really do some serious homework and come up with your choice of implants, and find a surgeon to match. If your are lucky, the two will coincide.
The approach is definitely up to the surgeons preference. I have spoken to surgeons will install either of the brands that you mentioned, and will give you a choice of which approach you would like with either brand.