This is recommended Gondukin,
1. Add SSEA to your NPPL(A)
I am in a similar situation.
This route closes soon. You must have your SSEA on your NPPL by April 8th 2018. After that date you'd need to do the EASA conversion 3 hours + skills test as you'd be working to EASA regs and licences.
Be aware that upgrading to a LAPL is easy but as a new LAPL licence holder there's the rolling recency requirements (12 hours PIC in previous 24 months) to meet before using the new licence. I have asked around and no one knows where I stand with this as the regulations are not designed for new NPPL holders having to convert immediately.