I was told by my Instructor... "The first 25 hours or so are the most challenging as this is building up the basic/fundamental general handling skills"... ready to get you in to the circuit.
So 1 lesson a week IMO may not be sufficient as you will forget things and may need to recap, if you add the glorious british weather at this time of year, and we have rain for 2-3 weeks you will find that you will be doing a lot of recap.
SFC will normally advise 2-3 lessons per week. What you could do depending on your Instructor... they may suggest that you book in 2 lessons a day.. For example, 10am and 2pm and if the morning is cancelled the afternoon may be better.
If you do this twice a week, there is a good chance you will fly. At SFC and probably most other schools things change relatively quickly.. so you will soon know if you are not flying in the form of a text!
Stapleford do not provide headsets.. However you can rent one for (I think) £10 per day with a small refundable deposit... There is a notice on the noticeboard by FORM 214 where you view the spot winds.
Across the other side (by the CFI office) you will find another noticeboard where headsets are advertised.
Personally, I purchased my own Pooley's Student Headset for around £50 ebay which does the job until I upgrade to another model.
Scoobster.