I would definitely be ringing your OS and organising a surgery date! It's been a few weeks since you saw him, hasn't it? My OS booked me in then and there the minute I said yes - I was going ahead with it! Then I only had to wait just over 4 weeks before having the surgery.
And as for what type of prosthesis you should have - I would be guided by what your OS recommends. He's the expert! I totally trust my doctor and was quite happy to go with whatever he wanted to use. (Titanium stem with metal cup and ceramic liner. Your doctor should explain in full why he uses what he uses, and answer whatever questions you might have. I actually booked in to see my OS about 2 weeks prior to my admitting date just so I could get my endless list of questions answered!
And he was more than happy to do so.
Just make the phone call - it will get the ball rolling! Good luck!
Peta