Preserving Residence for Naturalisation

Hello,

I am in the lengthy I130 process and should eventually get my green card.

I am a British National and want to live and work here (as I have a job contract here), but I want to be able to naturalise at the normal time too (after 3 years if I am not wrong - I am married to a US Citizen).

After I get my green card what should I do?

Should I apply for re-entry permits one after another until the 18 month minimum stay in the US is met?

OR

Should I apply for N-470 (Preserving Residence for Naturalisation)?

OR

Is there something else I am missing? My job has nothing to do with the US or its Goverment, it's and IT Consultancy position in the UK.

What is the best route for me to take to be able to:
1. Get my green card
2. Keep my green card and resident status while working and living in the UK
3. Apply for my naturalisation when the time comes

Also, how long will the shorted method take to naturalisation?

Thanks in advance!

BUMP - I really really badly need some help on this please.

Thanks!