In the German forums, most prefer the byshulz seat posts.
You could have done both with one of these:
Die D.2 ST-Ri – Absenkbare Parallelogramm Sattelstütze erhöht den Fahrkomfort dank der 80mm stufenlosen Absenkung und Federkonstruktion.
byschulz.com
Whilst not on a SuperDelite but an R&M with MIK & light mounted at handlebar i opted for a (slightly)
cheaper option:
Front (A$16.29):
Smarter Shopping, Better Living! Aliexpress.com
www.aliexpress.com
Rear: (A$21.66):
Smarter Shopping, Better Living! Aliexpress.com
www.aliexpress.com